Ink composition, ink set and recording method

ABSTRACT

An ink composition, which comprises: at least two kinds of water-soluble dyes each having the maximum wavelength of an absorption spectrum in an aqueous solvent of from 550 to 700 nm, wherein at least one of the at least two kinds of water-soluble dyes is selected from the group consisting of a compound represented by formula (L-1) as defined in the specification, a salt of the compound represented by formula (L-1) and a compound having a naphthalene ring substituted with at least one hydroxyl group and three or more azo groups; an ink set containing at least one kind of the ink composition; a recording method comprising applying the ink composition to a recording medium; and a recording method comprising loading the ink set on a recording apparatus, and applying the ink from the recording apparatus to a recording medium.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ink composition, an ink set, and arecording method, in particular, relates to an ink composition capableof forming an image having high fastness and high density.

2. Description of the Related Art

With the spread of the computer in recent years, ink jet printers havebeen widely used not only in offices but also in homes for printing onpapers, films and cloths.

As ink jet recording methods, a method of ejecting ink droplets byapplying pressure by piezo-elements, a method of ejecting ink dropletsby generating bubbles in ink by heat, a method of using ultrasonicwaves, and a method of suction ejection of ink droplets by electrostaticforce are known. As the ink compositions for these ink jet recordings,water ink, oil ink and solid ink (a melting type) are used. Of theseinks, water ink is mainly used for easiness of manufacture and handling,odors and safety.

Colorants used in inks for these ink jet recordings are required to havehigh solubility in solvents, to be capable of high density recording, tobe good in hue, to be excellent in fastness to light, heat, air, waterand chemicals, to have good fixing property to image-receiving materialsand to hardly blot, to be excellent in preservation property as inks, tobe free of toxicity, to be high in purity, and to be availableinexpensively. However, it is extremely difficult to search forcolorants that satisfy these requirements in high levels.

Various dyes and pigments have been already proposed for ink jetrecording and practically used but colorants satisfying all of theserequirements have not been discovered yet. It is difficult forconventionally known dyes and pigments having Color Index Nos. (C.I.) toreconcile the hue and fastness required of the inks for ink jetrecording.

Tris-azo dyestuffs and tetrakis-azo dyestuffs are discussed in recentyears as the dyes for black inks and disclosed in JP-A-2005-220211 (theterm “JP-A” as used herein refers to an “unexamined published Japanesepatent application”), JP-A-2004-28535 1, JP-A-2005-2271 and WO03/106572, but these dyestuffs do not come to sufficiently satisfy thedemands of the market, in particular on the fastness to gases andlights.

The present inventors have continued the examination of dyes good in hueand fastness and the development of dyes excellent for ink jetrecording. From these examinations, it has been found, as disclosed inJP-A-2005-162823, that it is effective to use a dye high in associationto increase fastness of images.

However, it has also been found that, when a dye having an associatingproperty is used, there arise problems of liability to bronzing(abnormal glossiness) at the high concentration area, and the reductionof image density as compared with a dye not having an associatingproperty.

SUMMARY OF THE INVENTION

An object of the invention is to provide a black ink composition for inkjet recording that is capable of excellent black tone and high densityprinting, excellent in image fastness, capable of restraining bronzeglossiness, free of blotting, and excellent in discoloration balance,another object is to provide an ink set containing the same, and afurther object is to provide a recording method using the same.

(1) An ink composition, which comprises:

at least two kinds of water-soluble dyes each having the maximumwavelength of an absorption spectrum in an aqueous solvent of from 550to 700 nm,

wherein at least one of the at least two kinds of water-soluble dyes isselected from the group consisting of a compound represented by formula(L-1), a salt of the compound represented by formula (L-1) and acompound having a naphthalene ring substituted with at least onehydroxyl group and three or more azo groups:

wherein A and B each independently represents an aromatic group that maybe substituted or a heterocyclic group that may be substituted, and A isa monovalent group and B is a divalent group;

T₁ and T₂ each independently represents ═CR₄₃— or —CR₄₄═, or either onerepresents a nitrogen atom and the other represents ═CR₄₃— or —CR₄₄═;

V₁, R₄₃ and R₄₄ each independently represents a hydrogen atom, a halogenatom, an alkyl group, an alkenyl group, an alkynyl group, an aralkylgroup, an aryl group, a heterocyclic group, a cyano group, a carboxylgroup, a carbamoyl group, an alkoxycarbonyl group, an aryloxycarbonylgroup, a heterocyclic oxycarbonyl group, an acyl group, a hydroxylgroup, an alkoxyl group, an aryloxy group, a heterocyclic oxy group, asilyloxy group, an acyloxy group, a carbamoyloxy group, analkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group, anacylamino group, a ureido group, a sulfamoylamino group, analkoxycarbonylamino group, an aryloxycarbonylamino group, analkylsulfonylamino group, an alkylsulfonylamino group, a heterocyclicsulfonylamino group, a nitro group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, an alkylsulfonyl group, anarylsulfonyl group, a heterocyclic sulfonyl group, an alkylsulfinylgroup, an arylsulfinyl group, a heterocyclic sulfinyl group, a sulfamoylgroup or a sulfo group, and each of these groups may further besubstituted;

R₄₁ and R₄₂ each independently represents a hydrogen atom, an alkylgroup, an alkenyl group, an alkynyl group, an aralkyl group, an arylgroup, a heterocyclic group, all acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, anarylsulfonyl group or a sulfamoyl group, and each of these groups mayfurther have a substituted, provided that R₄₁ and R₄₂ do not represent ahydrogen atom at the same time, and R₄₃ and R₄₁, or R₄₂, and R₄₂ may bebonded to each other to form a 5- or 6-membered ring, provided that thecompound represented by formula (L-1) contains at least one ionichydrophilic group.

(2) The ink composition as described in (1) above,

wherein the compound represented by formula (L-1) is a compoundrepresented by formula (L-2):

wherein X represents an N atom or ═CW₁—;

W₁ represents an electron attracting group having a Hammett'ssubstitution constant σp value of 0.20 or more;

A, V₁, T₁, T₂, R₄₁, and R₄₂ respectively have the same meaning as A, V₁,T₁, T₂, R₄₁ and R₄₂ in formula (L-1); and

W has the same meaning as V₁ in formula (L-1).

(3) The ink composition as described in (1) or (2) above,

wherein the compound represented by formula (L-2) is a compoundrepresented by formula (L-3):

wherein V₁, W, X, T₁, T₂, R₄₁ and R₄₂ respectively have the same meaningas V₁, W, X, T₁, T₂, R₄, and R₄₂ in formula (L-2); and

X₁, X₂, X₃, X₄, X₅, X₆ and X₇ each represents a monovalent group.

(4) The ink composition as described in any of (1) to (3) above, whichcomprises at least one compound represented by formula (L-1) and atleast one compound represented by formula (L-4) different in structurefrom each other:

wherein R₄₃ has the same meaning as R₄₃ in formula (L-1);

R₄₄ has the same meaning as R₄₄ in formula (L-1);

R₄₅ and R₄₆ each has the same meaning as R₄₁ and R₄₂ in formula (L-1);

R₄₁ and R₄₂ each has the same meaning as R₄₁ and R₄₂ in formula (L-1);

W has the same meaning as V₁ in formula (L-1); and

X₁, X₂, X₃, X₄, X₅, X₆ and X₇ each represents a monovalent group.

(5) The ink composition as described in any of (1) to (3) above, whichcomprises at least one compound represented by formula (L-1) and atleast one compound represented by formula (L-5) different in structurefrom each other:

wherein R₄₃ has the same meaning as R₄₃ in formula (L-1);

R₄₄ has the same meaning as R₄₄ in formula (L-1);

R₄₅ and R₄₆ each has the same meaning as R₄₁ and R₄₂ in formula (L-1);

R₄₁ and R₄₂ each has the same meaning as R₄₁ and R₄₂ in formula (L-1);

W has the same meaning as V₁ in formula (L-1);

W₁₁ represents an electron attracting group having a Hammett'ssubstitution constant σp value of 0.20 or more; and

X₁, X₂, X₃, X₄, X₅, X₆ and X₇ each represents a monovalent group.

(6) The ink composition as described in any of (1) to (5) above,

wherein the number of azo groups of the compound having a naphthalenering substituted with at least one hydroxyl group and three or more azogroups is five or less.

(7) The ink composition as described in any of (1) to (6) above,

wherein the compound having a naphthalene ring substituted with at leastone hydroxyl group and three or more azo groups contains one or moresulfonic acid group(s), one or more carboxyl group(s), or one or moresulfonic acid group(s) and one or more carboxyl group(s).

(8) The ink composition as described in any of (1) to (7) above,

wherein the compound having a naphthalene ring substituted with at leastone hydroxyl group and three or more azo groups is a compound selectedfrom the group consisting of a compound represented by any of formulae(L-6), (L-6a), (L-7) and (L-8) and a salt of the compound represented byany of formulae (L-6), (L-6a), (L-7) and (L-8):

wherein R₁₁ and R₁₂ each independently represents a hydrogen atom; ahalogen atom; a cyano group; a carboxyl group; a sulfo group; asulfamoyl group that may be substituted with an alkyl group or a phenylgroup; a phosphoric acid group; a nitro group; an acyl group; a ureidogroup; an alkyl group having from 1 to 4 carbon atoms that may besubstituted with a hydroxyl group or an alkoxyl group having from 1 to 4carbon atoms; an alkoxyl group having from 1 to 4 carbon atoms or anacylamino group that may be substituted with a hydroxyl group, analkoxyl group having from 1 to 4 carbon atoms, a sulfo group or acarboxyl group;

E represents a phenyl group or a naphthyl group, which may besubstituted with a halogen atom; a cyano group; a carboxyl group; asulfo group; a sulfamoyl group that may be substituted with an alkylgroup or a phenyl group; a phosphoric acid group; a nitro group; an acylgroup; a ureido group; an alkyl group having from 1 to 4 carbon atomsthat may be substituted with a hydroxyl group or an alkoxyl group havingfrom 1 to 4 carbon atoms; an alkoxyl group having from 1 to 4 carbonatoms or an acylamino group that may be substituted with a hydroxylgroup, an alkoxyl group having from 1 to 4 carbon atoms, a sulfo groupor a carboxyl group; and

n₁ represents 0 or 1;

wherein A represents formula (L-6a-1), and the substitution position ofA is the m- or p-position to the azo group;

R¹ and R² each independently represents a hydrogen atom; a halogen atom;a cyano group; a carboxyl group; a sulfo group; a sulfamoyl group; anN-alkylaminosulfonyl group; an N-phenylamino-sulfonyl group; a phosphogroup; a nitro group; an acyl group; a ureido group; an alkyl grouphaving from 1 to 4 carbon atoms that may be substituted with a hydroxylgroup or an alkoxyl group having from 1 to 4 carbon atoms; an alkoxylgroup having from 1 to 4 carbon atoms that may be substituted with ahydroxyl group, an alkoxyl group having from 1 to 4 carbon atoms, asulfo group or a carboxyl group; or an acylamino group that may besubstituted with an alkoxyl group having from 1 to 4 carbon atoms, asulfo group or a carboxyl group;

R³ and R⁴ each independently represents a hydrogen atom; a halogen atom;a cyano group; a carboxyl group; a sulfo group; a nitro group; an alkylgroup having from 1 to 4 carbon atoms; a hydroxyl group; or an alkoxylgroup having from 1 to 4 carbon atoms that may be substituted with analkoxyl group having from 1 to 4 carbon atoms or a sulfo group; and

n represents 0 or 1;

wherein R⁵ represents a cyano group; a carboxyl group; an alkyl grouphaving from 1 to 4 =carbon atoms; an alkoxycarbonyl group having from 1to 4 carbon atoms; or a phenyl group;

R⁶, R⁷ and R⁸ each independently represents a hydrogen atom; a halogenatom; a cyano group; a carboxyl group; a sulfo group; a nitro group; analkyl group having from 1 to 4 carbon atoms; an alkoxyl group havingfrom 1 to 4 carbon atoms that may be substituted with a hydroxyl group,an alkoxyl group having from 1 to 4 carbon atoms or a sulfo group; or anacylamino group that may be substituted with a hydroxyl group, analkoxyl group having from 1 to 4 carbon atoms or a sulfo group;

wherein G and J each independently represents a phenyl group or anaphthyl group that may be substituted, or a 5- or 6-membered aromaticheterocyclic group bonding to the azo group via a carbon atom, and eachof G and J contains at least one or more carboxyl group(s) or sulfogroup(s);

one of X and Y represents a hydroxyl group, and the other represents anamino group; and

l₂, m₂ and n₂ each independently represents 1 or 2;

wherein R₂₁ represents a phenyl group having a substituent, or anaphthyl group having a substituent;

R₂₂ represents a phenylene group having a substituent, or a naphthylenegroup having a substituent;

R₂₃ represents a 5- to 7-membered heterocyclic group having at least onedouble bond and a substituent; and

the substituents in R₂₁, R₂₂ and R₂₃ are each independently selectedfrom the group consisting of OH, SO₃H, PO₃H₂, CO₂H, NO₂, NH₂, an alkylgroup having from 1 to 4 carbon atoms, an alkyl group having from 1 to4-carbon atoms and a substituent, an alkoxyl group having from 1 to 4carbon atoms, an alkoxyl group having from 1 to 4 carbon atoms and asubstituent, an amino group, an amino group having a substituent and aphenyl group having a substituent.

(9) An ink composition, which comprises:

at least two kinds of water-soluble dyes each having the maximumwavelength of an absorption spectrum in an aqueous solvent of from 550to 700 nm,

wherein the at least two kinds of water-soluble dyes include: at leastone compound selected from the group consisting of a compoundrepresented by formula (L1) as described in (1), a compound representedby formula (L-2) as described in (2), a compound represented by formula(L-3) as described in (3), a compound represented by formula (L-4) asdescribed in (4) and a compound represented by formula (L-5) asdescribed in (5); and at least one compound selected from the groupconsisting of a compound represented by any of formulae (L-6), (L-6a),(L-7) and (L-8) and a salt of the compound represented by any offormulae (L-6), (L-6a), (L-7) and (L-8) as described in (8).

(10) The ink composition as described in (8) or (9) above,

wherein the compound represented by formula (L-8) is a compoundrepresented by formula (L-9):

wherein R₃₁ to R₃₉ each independently represents a group selected fromthe group consisting of H, OH, SO₃H, PO₃H₂, CO₂H, NO₂ and NH₂.

(11) The ink composition as described in any of (1) to (10) above, whichfurther comprises at least one kind of water-soluble dye having themaximum wavelength of an absorption spectrum in an aqueous solvent offrom 400 to 520 nm.

(12) The ink composition as described in (11) above, which comprises theat least one kind of water-soluble dye having the maximum wavelength ofan absorption spectrum in an aqueous solvent of from 400 to 520 nm in anamount of from 0.1 to 4 mass %.

(13) An ink set, which comprises at least one kind of an ink compositionas described in any of (1) to (12) above.

(14) A recording method, which comprises:

applying an ink composition as described in any of (1) to (12) above toa recording medium to conduct recording.

(15) A recording method, which comprises:

loading an ink set as described in (13) above on a recording apparatus;and

applying an ink from the recording apparatus to a recording medium toconduct recording.

(16) The recording method as described in (14) or (15) above, whichcomprises:

ejecting the ink composition from an ink jet nozzle to a recordingmedium to conduct recording.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be described in detail below.

The ink composition according to the invention contains at least twokinds of water-soluble dyes having the maximum wavelength of anabsorption spectrum in an aqueous solvent of from 550 to 700 nm(hereinafter referred to as “water-soluble long wave dyes L”), and atleast one of the water-soluble dyes is selected from the groupconsisting of a compound represented by the following formula (L-1), asalt thereof, and a compound having a naphthalene ring substituted withat least one hydroxyl group and three or more azo groups. The inkcomposition according to the invention is preferably used as black ink.

Water-Soluble Long Wave Dye L:

Water-soluble long wave dye L in the invention has the maximum of anabsorption spectrum (the absorption maximum) in an aqueous solvent offrom 550 to 700 nm. The maximum of an absorption spectrum (theabsorption maximum) in an aqueous solvent of water-soluble long wave dyeL is preferably from 560 to 680 nm, and more preferably from 570 to 650nm. It is preferred for these absorption spectra to have broadabsorption in a visible region, and the hue is preferably black, notbright hues such as magenta and cyan. The half value width of theabsorption spectra is preferably 100 nm or more (more preferably from120 to 500 nm, and still more preferably from 120 to 350 nm). Here, anaqueous solvent means a medium comprising water as the main solvent andmay contain an appropriate amount of a water-miscible organic solventcapable of dissolving or dispersing a dye. Further, an absorptionspectrum means an absorption spectrum that is measured with a usuallyused spectrophotometer using a cell of 1 cm. These are also the same asin the later-described water-soluble short wave dye S.

The absorption spectrum of water-soluble long wave dye L is anabsorption spectrum measured with a single compound. That is, when anabsorption spectrum in an aqueous solvent is measured, water-solublelong wave dye L in the invention means to show the physical propertiessuch as the desired absorption maximum and half value width not bycombining a plurality of compounds but to show these physical propertiesby a single compound. Incidentally, it is apparent in the invention thatas water-soluble long wave dyes L (hereinafter also referred to as “longwave dye L”), compounds having structures different from each other maybe used in combination so long as they satisfy the absorption spectra.Further, in the invention, dyes other than long wave dye L having theabsorption spectrum characteristics may be used in combination.

Further, as long wave dye L, a dye having such properties as capable ofassociation and whose reaction can be physically controlled is morepreferred.

Whether a dye is in an association state or not can be easily judged bythe measurement of visible absorption spectra by changing theconcentration of the dye, and judging whether the dye has an associatingproperty or not by the examination of the absorption maximum wavelength,the molar absorption coefficient and the change of wave form, andcomparing these solution physical properties and the absorption spectraof the dye on an image-receiving material.

Specifically, a preferred dye is a dye that forms the relationship ofε1/ε2>1.2 between the molar absorption coefficient (ε1) in the maximumwavelength of visible region absorption at the time when 0.1 mmol/literof a dye aqueous solution is measured with a cell of optical path lengthof 1 cm as defined in JP-A-2004-307831, and the molar absorptioncoefficient (ε2) at the time when 0.2 mol/liter of the aqueous solutionis measured with a liquid crystal cell of optical path length of 5 μm.

In the invention, as long wave dye L, at least one compound selectedfrom the group consisting of a compound represented by the followingformula (L-1), a salt thereof, and a compound having a naphthalene ringsubstituted with at least one hydroxyl group and three or more azogroups is contained.

In the following formula, the dye is shown as a free acid structure, butof course the dye may be used in the form of a salt in practical use.

In formula (L-1), A and B each represents an aromatic group that may besubstituted, or a heterocyclic group that may be substituted (A is amonovalent group and B is a divalent group).

T₁ and T₂ each represents ═CR₄₃— or —CR₄₄═, or either one represents anitrogen atom and the other represents ═CR₄₃— or —CR₄₄═. V₁, R₄₃ and R₄₄each represents a hydrogen atom, a halogen atom, an alkyl group, analkenyl group, an alkynyl group, an aralkyl group, an aryl group, aheterocyclic group, a cyano group, a carboxyl group, a carbamoyl group,an alkoxycarbonyl group, an aryloxycarbonyl group, a heterocyclicoxycarbonyl group, an acyl group, a hydroxyl group, an alkoxyl group, anaryloxy group, a heterocyclic oxy group, a silyloxy group, an acyloxygroup, a carbamoyloxy group, an alkoxycarbonyloxy group, anaryloxycarbonyloxy group, an amino group (in this specification, themeaning of an amino group includes not only an unsubstituted amino groupbut also an alkylamino group, an arylamino group and a heterocyclicamino group), an acylamino group, a ureido group, a sulfamoylaminogroup, an alkoxycarbonylamino group, an aryloxycarbonylamino group, analkylsulfonylamino group, an arylsulfonylamino group, a heterocyclicsulfonylamino group, a nitro group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, an alkylsulfonyl group, anarylsulfonyl group, a heterocyclic sulfonyl group, an alkylsulfinylgroup, an arylsulfinyl group, a heterocyclic sulfinyl group, a sulfamoylgroup, or a sulfo group, and each of these groups may further besubstituted. R₄₁ and R₄₂ each represents a hydrogen atom, an alkylgroup, an alkenyl group, an alkynyl group, an aralkyl group, an arylgroup, a heterocyclic group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, anarylsulfonyl group, or a sulfamoyl group, and each of these groups mayfurther have a substituted, provided that R₄₁ and R₄₂ do not represent ahydrogen atom at the same time, and R₄₃ and R₄₁, or R₄₁, and R₄₂ may bebonded to each other to form a 5- or 6-membered ring.

Formula (L-1) will be described in detail below.

In formula (L-1), A preferably represents a monovalent aromatic groupthat may be substituted, or a monovalent heterocyclic group that may besubstituted, more preferably a substituted phenyl group, a substitutednaphthyl group, or a substituted or unsubstituted heterocyclic group,and of these, a phenyl group and a naphthyl group substituted with anionic hydrophilic group, and a 5- or 6-membered nitrogen-containingheterocyclic ring having a substituent are preferred, in particular aphenyl group and a naphthyl group substituted with a sulfo group(including the salts thereof) or a carboxyl group (including the saltsthereof) are preferred, and a phenyl group and a naphthyl groupsubstituted with 2 or more sulfo groups (including the salts thereof) orcarboxyl groups (including the salts thereof) are more preferred, and anaphthyl group substituted with 2 or 3 sulfo groups (including the saltsthereof) is most preferred.

In formula (L-1), B represents a divalent aromatic group that may besubstituted or a divalent heterocyclic group that may be substituted,more specifically B preferably represents a 5- or 6-memberedheterocyclic group having a substituent, and a 5-membered heterocyclicgroup having a substituent is more preferred. The 5- or 6-memberedheterocyclic ring means a 5- or 6-membered ring containing a heteroatom. As the hetero atom of the heterocyclic ring, N, S and O atoms areexemplified.

The heterocyclic ring represented by B may be condensed with analiphatic group, an aromatic ring, or other heterocyclic ring, and theheterocyclic ring may have a substituent on the condensed ring. Theheterocyclic ring represented by B means both a saturated heterocyclicring and an unsaturated heterocyclic ring, and an unsaturatedheterocyclic ring is preferred. In the case of a nitrogen-containingheterocyclic ring, the N atom may be quaternized. Further, with respectto a heterocyclic ring of tautomerism, when one alone of tautomers isdescribed, it also includes the other tautomer.

As especially preferred heterocyclic rings represented by B, a pyridinering, a pyrazine ring a pyrimidine ring, a pyridazine ring, a thiophenering, a thiazole ring, an imidazole ring, a benzothiazole ring, and athienothiazole ring are exemplified.

In formula (L-1), T₁ and T₂ each represents ═CR₄₃— or —CR₄═, or eitherone represents a nitrogen atom and the other represents ═CR₄₃— or—CR₄₄═, but the case where T₁ and T₂ each represents ═CR₄₃— or —CR₄₄═ ispreferred for the reason of capable of exhibiting more excellentperformance.

In formula (L-1), R₄₁ and R₄₂ each represents a hydrogen atom, an alkylgroup, an alkenyl group, an alkynyl group, an aralkyl group, an arylgroup, a heterocyclic group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, anarylsulfonyl group, or a sulfamoyl group, and each of these groups mayfurther have a substituted. Of these groups, a hydrogen atom, an alkylgroup, an aryl group, a heterocyclic group, an acyl group, analkylsulfonyl group, and an arylsulfonyl group are preferred, further, ahydrogen atom, an alkyl group, an aryl group, and a heterocyclic groupare more preferred, a hydrogen atom, an aryl group having a substituent,and a heterocyclic group having a substituent are especially preferred,and a hydrogen atom and an aryl group having a substituent are mostpreferred. However, R₄₁ and R₄₂ do not represent a hydrogen atom at thesame time, and R₄₃ and R₄₁, or R₄₁, and R₄₂ may be bonded to each otherto form a 5- or 6-membered ring.

In formula (L-1), V₁ preferably represents a hydrogen atom, a halogenatom, an alkyl group, an alkenyl group, an alkynyl group, an aralkylgroup, an aryl group, a heterocyclic group, a hydroxyl group, an alkoxylgroup, an, aryloxy group, a heterocyclic oxy group, a silyloxy group, anacyloxy group, an amino group (including an alkylamino group, anarylamino group, and a heterocyclic amino group), an acylamino group, aureido group, a sulfamoylamino group, an alkoxycarbonylamino group, anaryloxycarbonylamino group, an alkylthio group, an arylthio group, or aheterocyclic thio group, and each of these groups may further besubstituted.

V₁ more preferably represents a hydrogen atom, a halogen atom, an alkylgroup, a hydroxyl group, an alkoxyl group, an aryloxy group, aheterocyclic oxy group, a silyloxy group, an acyloxy group, an aminogroup (including an alkylamino group, an arylamino group, and aheterocyclic amino group), or an acylamino group. Of these groups, ahydrogen atom, an amino group (including an alkylamino group, anarylamino group, and a heterocyclic amino group), and an acylamino groupare preferred, an amino group having a substituent is especiallypreferred, and an amino group substituted with an aryl group having anionic hydrophilic group as the substituent (e.g., a substituted anilinogroup, etc.) is most preferred.

The ionic hydrophilic groups include a sulfo group, a carboxyl group, aphosphono group, a quaternary ammonium group, etc. As the ionichydrophilic groups, a carboxyl group, a phosphono group, and a sulfogroup are preferred, a carboxyl group and a sulfo group are especiallypreferred, and a sulfo group is most preferred from the viewpoint ofincreasing solubility in an aqueous solvent. A carboxyl group, aphosphono group, and a sulfo group may be in the state of a salt, andthe examples of the counter salts include ammonium, alkali metal (e.g.,lithium, sodium, potassium), and organic cation (e.g.,tetramethylammonium, tetramethylguanidinium, tetramethylphosphonium). Asthe counter salts, ammonium, lithium, sodium and potassium arepreferred, sodium and lithium are more preferred, and lithium is mostpreferred.

The especially preferred combinations as the compounds represented byformula (L-1) are combinations containing the following (a) to (e).

-   (a) A preferably represents a substituted phenyl group, a    substituted naphthyl group, or a substituted or unsubstituted    heterocyclic group, and of these, a phenyl group and a naphthyl    group substituted with an ionic hydrophilic group, and a 5- or    6-membered nitrogen-containing heterocyclic ring having a    substituent are preferred, in particular a phenyl group and a    naphthyl group substituted with a sulfo group (including the salts    thereof) or a carboxyl group (including the salts thereof) are    preferred, a phenyl group and a naphthyl group substituted with 2 or    more sulfo groups (including the salts thereof) or carboxyl groups    (including the salts thereof) are more preferred, and a naphthyl    group substituted with 2 or 3 sulfo groups (including the salts    thereof) is most preferred.-   (b) B preferably represents a 5- or 6-membered heterocyclic group    having a substituent, and a 5-membered heterocyclic group having a    substituent is more preferred As especially preferred heterocyclic    rings, a pyridine ring, a pyrazine ring a pyrimidine ring, a    pyridazine ring, a thiophene ring, a thiazole ring, an imidazole    ring, a benzothiazole ring, and a thienothiazole ring are    exemplified.-   (c) T₁ and T₂ each represents ═CR₄₃— or —CR₄₄═, or either one    represents a nitrogen atom and the other represents ═CR₄₃— or    —CR₄₄═, but the case where T₁ and T₂ each represents ═CR₄₃— or    —CR₄₄═ is preferred for the reason of capable of exhibiting more    excellent performance.-   (d) R₄₁ and R₄₂ each preferably represents a hydrogen atom, an alkyl    group, an aryl group, a heterocyclic group, an acyl group, an    alkylsulfonyl group, or an arylsulfonyl group, more preferably a    hydrogen atom, an alkyl group, an aryl group, or a heterocyclic    group, especially preferably a hydrogen atom, an aryl group having a    substituent, or a heterocyclic group having a substituent, and most    preferably a hydrogen atom or an aryl group having a substituent.    However, R₄₁ and R₄₂ do not represent a hydrogen atom at the same    time, and R₄₃ and R₄₁, or R₄₁ and R₄₂ may be bonded to each other to    form a 5- or 6-membered ring.-   (e) V₁ represents a hydrogen atom, a halogen atom, an alkyl group, a    hydroxyl group, an alkoxyl group, an aryloxy group, a heterocyclic    oxy group, a silyloxy group, an acyloxy group, an amino group    (including an alkylamino group, an arylamino group, and a    heterocyclic amino group), or an acylamino group, preferably a    hydrogen atom, an amino group (including an alkylamino group, an    arylamino group, and a heterocyclic amino group), or an acylamino    group, especially preferably an amino group having a substituent,    and most preferably an amino group substituted with an aryl group    having an ionic hydrophilic group as the substituent (e.g., a    substituted anilino group, etc.).

Regarding combination of the preferred substituents of the dyestuffrepresented by formula (L-1), a compound wherein at least one of varioussubstituents is the above preferred group is preferred, a compoundwherein more substituents of various substituents are the abovepreferred groups is more preferred, and a compound wherein all thesubstituents are the preferred groups is most preferred.

The compound represented by formula (L-1) is preferably a compoundrepresented by the following formula (L-2).

In formula (L-2), X represents an N atom or ═CW₁—; W₁ represents anelectron attracting group having a Hammett's substitution constant σpvalue of 0.20 or more; A, V₁, T₁, T₂, R₄₁ and R₄₂ respectively have thesame meaning as A, V₁, T₁, T₂, R₄₁ and R₄₂ in formula (L-1); and W hasthe same meaning as V₁ in formula (L-1).

Formula (L-2) will be described in detail below.

In formula (L-2), W preferably represents a substituted phenyl group, asubstituted or unsubstituted naphthyl group, or a substituted orunsubstituted heterocyclic group (e.g., a pyrrole ring, a thiophenering, an imidazole ring, a thiazole ring, a benzothiazole ring, apyridine ring, or a pyridazine ring), and especially preferably asubstituted phenyl group (in particular, a phenyl group substituted atthe para-position), a substituted or unsubstituted β-naphthyl group, apyridine ring, or a thiazole ring.

In formula (L-2), X represents an N atom or ═CW₁—, W₁ represents anelectron attracting group having a Hammett's substitution constant σpvalue of 0.20 or more. An electron attracting group having a up value of0.30 or more is preferred, 0.45 or more is more preferred, and 0.60 ormore is especially preferred, but it is desired that the Hammett'ssubstitution constant σp value does not exceed 1.0. More specifically,W₁ preferably represents an acyl group having from 2 to 20 carbon atoms,an alkyloxycarbonyl group having from 2 to 20 carbon atoms, a nitrogroup, a cyano group, an alkylsulfonyl group having from 1 to 20 carbonatoms, an arylsulfonyl group having from 6 to 20 carbon atoms, acarbamoyl group having from 1 to 20 carbon atoms, or a halogenated alkylgroup having from 1 to 20 carbon atoms, especially preferably representsa cyano group, an alkylsulfonyl group having from 1 to 20 carbon atoms,or an arylsulfonyl group having from 6 to 20 carbon atoms, and mostpreferably a cyano group.

In formula (L-2), A has the same meaning as A in formula (L-1), and thepreferred examples are also the same.

In formula (L-2), T₁ and T₂ each has the same meaning as T₁ and T₂ informula (L-1), and the preferred examples are also the same.

In formula (L-2), R₄₁ and R₄₂ each has the same meaning as R₄₁ and R₄₂in formula (L-1), and the preferred examples are also the same.

In formula (L-2), V₁ has the same meaning as V₁ in formula (L-1), andthe preferred examples are also the same.

The especially preferred combinations as the compounds represented byformula (L-2) are combinations containing the following (a) to (f).

-   (a) W preferably represents a substituted phenyl group, a    substituted or unsubstituted naphthyl group, or a substituted or    unsubstituted heterocyclic group (e.g., a pyrrole ring, a thiophene    ring, an imidazole ring, a thiazole ring, a benzothiazole ring, a    pyridine ring, or a pyridazine ring), and especially preferably a    substituted phenyl group (in particular, a phenyl group substituted    at the para-position), a substituted or unsubstituted β-naphthyl    group, a pyridine ring, or a thiazole ring.-   (b) X represents an N atom or ═CW₁—, and W₁ represents an electron    attracting group having a Hammett's substitution constant σp value    of 0.20 or more. More specifically, W₁ preferably represents an acyl    group having from 2 to 20 carbon atoms, an alkyloxycarbonyl group    having from 2 to 20 carbon atoms, a nitro group, a cyano group, an    alkylsulfonyl group having from 1 to 20 carbon atoms, an    arylsulfonyl group having from 6 to 20 carbon atoms, a carbamoyl    group having from 1 to 20 carbon atoms, or a halogenated alkyl group    having from 1 to 20 carbon atoms, especially preferably a cyano    group, an alkylsulfonyl group having from 1 to 20 carbon atoms, or    an arylsulfonyl group having from 6 to 20 carbon atoms, and most    preferably a cyano group.-   (c) A preferably represents a substituted phenyl group, a    substituted naphthyl group, or a substituted or unsubstituted    heterocyclic group, and more preferably a phenyl group or a naphthyl    group substituted with an ionic hydrophilic group, or a 5- or    6-membered nitrogen-containing heterocyclic ring having a    substituent, especially preferably a phenyl group or a naphthyl    group substituted with a sulfo group (including the salts thereof)    or a carboxyl group (including the salts thereof), and still more    preferably a phenyl group or a naphthyl group substituted with 2 or    more sulfo groups (including the salts thereof) or carboxyl groups    (including the salts thereof), and most preferably a naphthyl group    substituted with 2 or 3 sulfo groups (including the salts thereof).-   (d) T₁ and T₂ each represents ═CR₄₃— or —CR₄₄═, or either one    represents a nitrogen atom and the other represents ═CR₃— or —CR₄₄═,    but the case where T₁ and T₂ each represents ═CR₄₃— or —CR₄₄═ is    preferred for the reason of capable of exhibiting more excellent    performance.-   (e) R₄₁ and R₄₂ each preferably represents a hydrogen atom, an alkyl    group, an aryl group, a heterocyclic group, an acyl group, an    alkylsulfonyl group, or an arylsulfonyl group, more preferably a    hydrogen atom, an alkyl group, an aryl group, or a heterocyclic    group, especially preferably a hydrogen atom, an aryl group having a    substituent, or a heterocyclic group having a substituent, and most    preferably a hydrogen atom or an aryl group having a substituent.    However, R₄₁ and R₄₂ do not represent a hydrogen atom at the same    time, and R₄₃ and R₄₁, or R₄₁ and R₄₂ may be bonded to each other to    form a 5- or 6-membered ring.-   (f) V, represents a hydrogen atom, a halogen atom, an alkyl group, a    hydroxyl group, an alkoxyl group, an aryloxy group, a heterocyclic    oxy group, a silyloxy group, an acyloxy group, an amino group    (including an alkylamino group, an arylamino group, and a    heterocyclic amino group), or an acylamino group, preferably a    hydrogen atom, an amino group (including an alkylamino group, an    arylamino group, and a heterocyclic amino group), or an acylamino    group, especially preferably an amino group having a substituent,    and most preferably an amino group substituted with an aryl group    having an ionic hydrophilic group as the substituent (e.g., a    substituted anilino group, etc.).

Regarding combination of the preferred substituents of the dyestuffrepresented by formula (L-2), a compound wherein at least one of varioussubstituents is the above preferred group is preferred, a compoundwherein more substituents of various substituents are the abovepreferred groups is more preferred, and a compound wherein all thesubstituents are the preferred groups is most preferred.

The compound represented by formula (L-2) is preferably a compoundrepresented by the following formula (L-3).

In formula (L-3), V₁, W, X, T₁, T₂, R₄₁ and R₄₂ respectively have thesame meaning as V₁, W, X, T₁, T₂, R₄₁ and R₄₂ in formula (L-2), and X₁,X₂, X₃, X₄, X₅, X₆ and X₇ each has the same meaning as V₁ in formula(L-1).

Formula (L-3) will be described in detail below.

In formula (L-3), the monovalent group represented by X₁, X₂, X₃, X₄,X5, X₆ and X₇ is a hydrogen atom or a monovalent substituent. Themonovalent substituent will be described in further detail. The examplesof the monovalent substituents include a halogen atom, an alkyl group, acycloalkyl group, an aralkyl group, an alkenyl group, an alkynyl group,an aryl group, a heterocyclic group, a cyano group, a hydroxyl group, anitro group, an alkoxyl group, an aryloxy group, a silyloxy group, aheterocyclic oxy group, an acyloxy group, a carbamoyloxy group, analkoxycarbonyloxy group, an aryloxy-carbonyloxy group, an amino group(an alkylamino group, an arylamino group), an acylamino group (an amidogroup), an aminocarbonylamino group (a ureido group), analkoxycarbonyl-amino group, an aryloxycarbonylamino group, asulfamoylamino group, an alkylsulfonylamino group, an arylsulfonylaminogroup, an alkylthio group, an arylthio group, a heterocyclic thio group,a sulfamoyl group, an alkylsulfinyl group, an arylsulfinyl group, analkylsulfonyl group, an arylsulfonyl group, an acyl group, anaryloxycarbonyl group, an alkoxy-carbonyl group, a carbamoyl group, aphosphino group, a phosphinyl group, a phosphinyloxy group, aphosphinylamino group, a silyl group, an azo group, and an imido group,and each of these groups may further have a substituent.

X₁, X₂, X₃, X₄, X₅, X₆ and X₇ each preferably represents a hydrogenatom, a halogen atom, an alkyl group, an aryl group, a heterocyclicgroup, a cyano group, an alkoxyl group, an amido group, a ureido group,an alkylsulfonylamino group, an arylsulfonylamino group, a sulfamoylgroup, an alkylsulfonyl group, an arylsulfonyl group, a carbamoyl group,an alkoxy-carbonyl group, a sulfo group (including the salts thereof), acarboxyl group (including the salts thereof), a hydroxyl group (or thesalts thereof), a phosphono group (or the salts thereof), or quaternaryammonium and of these substituents, a hydrogen atom, a halogen atom, analkyl group, a sulfo group (including the salts thereof), a carboxylgroup (including the salts thereof), and a hydroxyl group (or the saltsthereof) are preferred, and a hydrogen atom, a sulfo group (includingthe salts thereof), and a carboxyl group (including the salts thereof)are further preferred, in particular it is preferred that at least oneof X₁, X₂, X₃, X₄, X₅, x₆ and X₇ represents a sulfo group (including thesalts thereof) or a carboxyl group (including the salts thereof).

In formula (L-3), W has the same meaning as W in formula (L-2), and thepreferred examples are also the same.

In formula (L-3), X has the same meaning as X in formula (L-2), and thepreferred examples are also the same.

In formula (L-3), T₁ and T₂ each has the same meaning as T₁ and T₂ informula (L-2), and the preferred examples are also the same.

In formula (L-3), R₄₁ and R₄₂ each has the same meaning as R₄₁ and R₄₂in formula (L-2), and the preferred examples are also the same.

In formula (L-3), V₁ has the same meaning as V₁ in formula (L-2), andthe preferred examples are also the same.

The especially preferred combinations as the compounds represented byformula (L-3) are combinations containing the following (a) to (f).

-   (a) X₁, X₂, X₃, X₄, X₅, X₆ and X₇ each represents a hydrogen atom, a    halogen atom, an alkyl group, an aryl group, a heterocyclic group, a    cyano group, an alkoxyl group, an amido group, a ureido group, an    alkylsulfonylamino group, an arylsulfonylamino group, a sulfamoyl    group, an alkylsulfonyl group, an arylsulfonyl group, a carbamoyl    group, an alkoxycarbonyl group, a sulfo group (including the salts    thereof), a carboxyl group (including the salts thereof), a hydroxyl    group (or the salts thereof), a phosphono group (or the salts    thereof), or quaternary ammonium, and of these substituents, a    hydrogen atom, a halogen atom, an alkyl group, a sulfo group    (including the salts thereof), a carboxyl group (including the salts    thereof), and a hydroxyl group (Or the salts thereof) are preferred,    and a hydrogen atom, a sulfo group (including the salts thereof),    and a carboxyl group (including the salts thereof) are further    preferred, in particular it is preferred that at least one of X₁,    X₂, X₃, X₄, X₅, X₆ and X₇ represents a sulfo group (including the    salts thereof) or a carboxyl group (including the salts thereof).-   (b) W preferably represents a substituted phenyl group, a    substituted or unsubstituted naphthyl group, or a substituted or    unsubstituted heterocyclic group (e.g., a pyrrole ring, a thiophene    ring, an imidazole ring, a thiazole ring, a benzothiazole ring, a    pyridine ring, or a pyridazine ring), and especially preferably a    substituted phenyl group (in particular, a phenyl group substituted    at the para-position), a substituted or unsubstituted β-naphthyl    group, a pyridine ring, or a thiazole ring.-   (c) X represents an N atom or ═CW₁—, and W₁ represents an electron    attracting group having a Hammett's substitution constant σp value    of 0.20 or more. More specifically, W₁ preferably represents an acyl    group having from 2 to 20 carbon atoms, an alkyloxycarbonyl group    having from 2 to 20 carbon atoms, a nitro group, a cyano group, an    alkylsulfonyl group having from 1 to 20 carbon atoms, an    arylsulfonyl group having from 6 to 20 carbon atoms, a carbamoyl    group having from 1 to 20 carbon atoms, or a halogenated alkyl group    having from 1 to 20 carbon atoms, especially preferably a cyano    group, an alkylsulfonyl group having from 1 to 20 carbon atoms, or    an arylsulfonyl group having from 6 to 20 carbon atoms, and most    preferably a cyano group.-   (d) T₁ and T₂ each represents ═CR₄₃— or —C₄₄═, or either one    represents a nitrogen atom and the other represents ═CR₄₃— or —C₄₄═,    but the case where T₁ and T₂ each represents ═CR₄₃— or —CR₄₄═ is    preferred for the reason of capable of exhibiting more excellent    performance.-   (e) R₄, and R₄₂ each preferably represents a hydrogen atom, an alkyl    group, an aryl group, a heterocyclic group, an acyl group, an    alkylsulfonyl group, or an arylsulfonyl group, more preferably a    hydrogen atom, an alkyl group, an aryl group, or a heterocyclic    group, especially preferably a hydrogen atom, an aryl group having a    substituent, or a heterocyclic group having a substituent, and most    preferably a hydrogen atom or an aryl group having a substituent.    However, R₄₁ and R₄₂ do not represent a hydrogen atom at the same    time, and R₄₃ and R₄₁, or R₄₁ and R₄₂ may be bonded to each other to    form a 5- or 6-membered ring.-   (f) V₁ represents a hydrogen atom, a halogen atom, an alkyl group, a    hydroxyl group, an alkoxyl group, an aryloxy group, a heterocyclic    oxy group, a silyloxy group, an acyloxy group, an amino group    (including an alkylamino group, an arylamino group, and a    heterocyclic amino group), or an acylamino group, preferably a    hydrogen atom, an amino group (including an alkylamino group, an    arylamino group, and a heterocyclic amino group), or an acylamino    group, especially preferably an amino group having a substituent,    and most preferably an amino group substituted with an aryl group    having an ionic hydrophilic group as the substituent (e.g., a    substituted anilino group, etc.).

Regarding combination of the preferred substituents of the dyestuffrepresented by formula (L-3), a compound wherein at least one of varioussubstituents is the above preferred group is preferred, a compoundwherein more substituents of various substituents are the abovepreferred groups is more preferred, and a compound wherein all thesubstituents are the preferred groups is most preferred.

The compound represented by formula (L-3) is preferably a compoundrepresented by the following formula (L-4) and/or the following formula(L-5).

In formula (L-4), R₄₃ has the same meaning as R₄₃ in formula (L-1); R₄₄has the same meaning as R₄₄ in formula (L-1); R₄₅ and R₄₆ each has thesame meaning as R₄₁ and R₄₂ in formula (L-1); and R₄₁ and R₄₂ each hasthe same meaning as R₄₁ and R₄₂ in formula (L-1).

W has the same meaning as W in formula (L-3); and X₁, X₂, X₃, X₄, X₅, X₆and X₇ each has the same meaning as. X₁, X₂, X₃, X₄, X₅, X₆ and X₇ informula (L-3).

In formula (L-5), R₄₃ has the same meaning as R₄₃ in formula (L-1); R₄₄has the same meaning as R₄₄ in formula (L-1); R₄₅ and R₄₆ each has thesame meaning as R₄₁ and R₄₂ in formula (L-3); R₄₁ and R₄₂ each has thesame meaning as R₄₁ and R₄₂ in formula (L-3); W has the same meaning asW in formula (L-3); W₁₁ has the same meaning as W₁ in formula (L-2); andX₁, X₂, X₃, X₄, X₅, X₆ and X₇ each has the same meaning as X₁, X₂, X₃,X₄, X₅, X₆ and X₇ in formula (L-3).

Formula (L-4) is described in detail below.

Tn formula (L-4), X₁, X₂, X₃, X₄, X₅, X₆ and X₇ each has the samemeaning as X₁, X₂, X₃, X₄, X₅, X₆ and X₇ in formula (L3), and thepreferred examples are also the same.

In formula (L-4), W has the same meaning as W in formula (L-3), and thepreferred examples are also the same.

In formula (L-4), R₄₁ and R₄₂ each has the same meaning as R₄₁ and R₄₂in formula (L-3), and the preferred examples are also the same.

In formula (L-4), R₄₃ and R₄₄ each has the same meaning as R₄₃ and R₄₄in formula (L-1), and the preferred examples are also the same.

In formula (L-1), R₄₅ and R₄₆ each has the same meaning as R₄₁ and R₄₂in formula (L-3), and the preferred examples are also the same.

The especially preferred combinations as the compounds represented byformula (L-4) are combinations containing the following (a) to (e).

-   (a) X₁, X₂, X₃, X₄, X₅, X₆ and X₇ each represents a hydrogen atom, a    halogen atom, an alkyl group, an aryl group, a heterocyclic group, a    cyano group, an alkoxyl group, an amido group, a ureido group, an    alkylsulfonylamino group, an arylsulfonylamino group, a sulfamoyl    group, an alkylsulfonyl group, an arylsulfonyl group, a carbamoyl    group, an alkoxycarbonyl group, a sulfo group (including the salts    thereof), a carboxyl group (including the salts thereof), a hydroxyl    group (or the salts thereof), a phosphono group (or the salts    thereof), or quaternary ammonium, and of these substituents, a    hydrogen atom, a halogen atom, an alkyl group, a sulfo group    (including the salts thereof), a carboxyl group (including the salts    thereof), and a hydroxyl group (or the salts thereof) are preferred,    and a hydrogen atom, a sulfo group (including the salts thereof),    and a carboxyl group (including the salts thereof) are further    preferred, in particular it is preferred that at least one of X₁,    X₂, X₃, X₄, X₅, X₆ and X₇ represents a sulfo group (including the    salts thereof) or a carboxyl group (including the salts thereof).-   (b) W preferably represents a substituted phenyl group, a    substituted or unsubstituted naphthyl group, or a substituted or    unsubstituted heterocyclic group (e.g., a pyrrole ring, a thiophene    ring, an imidazole ring, a thiazole ring, a benzothiazole ring, a    pyridine ring, or a pyridazine ring), and especially preferably a    substituted phenyl group (in particular, a phenyl group substituted    at the para-position), a substituted or unsubstituted β-naphthyl    group, a pyridine ring, or a thiazole ring.-   (c) R₄₁ and R₄₂ each preferably represents a hydrogen atom, an alkyl    group, an aryl group, a heterocyclic group, an acyl group, an    alkylsulfonyl group, or an arylsulfonyl group, more preferably a    hydrogen atom, an alkyl group, an aryl group, or a heterocyclic    group, especially preferably a hydrogen atom, an aryl group having a    substituent, or a heterocyclic group having a substituent, and most    preferably a hydrogen atom or an aryl group having a substituent.    However, R₄₁ and R₄₂ do not represent a hydrogen atom at the same    time, and R₄₃ and R₄₁, or R₄₁ and R₄₂ may be bonded to each other to    form a 5- or 6-membered ring.-   (d) R₄₃ and R₄₄ each preferably represents a hydrogen atom, a    halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an    aralkyl group, an aryl group, a heterocyclic group, a cyano group, a    carboxyl group, a carbamoyl group, an alkoxycarbonyl group, an    aryloxycarbonyl group, a heterocyclic oxycarbonyl group, a hydroxyl    group, an amino group (including an alkylamino group, an arylamino    group, and a heterocyclic amino group), an acylamino group, a ureido    group, a sulfamoylamino group, an alkoxycarbonylamino group, an    aryloxycarbonylamino group, an alkylsulfonylamino group, an    arylsulfonylamino group, or a heterocyclic sulfonylamino group, and    each group may further be substituted.

R₄₃ more preferably represents a hydrogen atom, a halogen atom, an arylgroup, a heterocyclic group, a cyano group, a carboxyl group, acarbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, or aheterocyclic oxycarbonyl group, still more preferably a cyano group, acarboxyl group, a carbamoyl group, or an alkoxycarbonyl group, andespecially preferably a cyano group.

R₄₄ more preferably represents a hydrogen atom, a halogen atom, an alkylgroup, an alkenyl group, an alkynyl group, an aralkyl group, an arylgroup, a heterocyclic group, a hydroxyl group, an amino group (includingan alkylamino group, an arylamino group, and a heterocyclic aminogroup), an acylamino group, a ureido group, a sulfamoylamino group, analkoxy-carbonylamino group, an aryloxycarbonylamino group, analkylsulfonylamino group, an arylsulfonylamino group, or a heterocyclicsulfonylamino group, still more preferably a hydrogen atom, a halogenatom, an alkyl group, an alkenyl group, an alkynyl group, an aralkylgroup, or an aryl group, and most preferably a methyl group.

-   (c) R₄₅ and R₄₆ each preferably represents a hydrogen atom, an alkyl    group, an aryl group, a heterocyclic group, an acyl group, an    alkylsulfonyl group, or an arylsulfonyl group, and more preferably a    hydrogen atom, an alkyl group, an aryl group, or a heterocyclic    group, especially preferably a hydrogen atom, an aryl group having a    substituent, or a heterocyclic group having a substituent, and most    preferably a hydrogen atom or an aryl group having a substituent.    However, R₄₅ and R₄₆ do not represent a hydrogen atom at the same    time, and R₄₅ and R₄₆ may be bonded to each other to form a 5- or    6-membered ring.

Regarding combination of the preferred substituents of the dyestuffrepresented by formula (L-4), a compound wherein at least one of varioussubstituents is the above preferred group is preferred, a compoundwherein more substituents of various substituents are the abovepreferred groups is more preferred, and a compound wherein all thesubstituents are the preferred groups is most preferred.

Formula (L-5) is described in detail below.

In formula (L-5), X₁, X₂, X₃, X₄, X₅, X₆ and X₇ each has the samemeaning as X₁, X₂, X₃, X₄, X₅, X₆ and X₇ in formula (L-3), and thepreferred examples are also the same.

In formula (L-5), W has the same meaning as W in formula (L-3), and thepreferred examples are also the same.

In formula (L-5), W₁₁ has the same meaning as W₁ in formula (L-2), andthe preferred examples are also the same.

In formula (L-5), R₄₁ and R₄₂ each has the same meaning as R₄₁ and R₄₂in formula (L-3), and the preferred examples are also the same.

In formula (L-5), R₄₃ and R₄₄ each has the same meaning as R₄₃ and R₄₄in formula (L-1), and the preferred examples are also the same.

In formula (L-5), R₄₅ and R₄₆ each has the same meaning as R₄₁ and R₄₂in formula (L-3), and the preferred examples are also the same.

The especially preferred combinations as the compounds represented byformula (L-5) are combinations containing the following (a) to (f).

-   (a) X₁, X₂, X₃, X₄, X₅, X₆ and X₇ each represents a hydrogen atom, a    halogen atom, an alkyl group, an aryl group, a heterocyclic group, a    cyano group, an alkoxyl group, an amido group, a ureido group, an    alkylsulfonylamino group, an arylsulfonylamino group, a sulfamoyl    group, an alkylsulfonyl group, an arylsulfonyl group, a carbamoyl    group, an alkoxycarbonyl group, a sulfo group (including the salts    thereof), a carboxyl group (including the salts thereof), a hydroxyl    group (or the salts thereof), a phosphono group (or the salts    thereof), or quaternary ammonium, and of these substituents, a    hydrogen atom, a halogen atom, an alkyl group, a sulfo group    (including the salts thereof), a carboxyl group (including the salts    thereof), and a hydroxyl group (or the salts thereof) are preferred,    and a hydrogen atom, a sulfo group (including the salts thereof),    and a carboxyl group (including the salts thereof) are firer    preferred, ill particular it is preferred that at least one of X₁,    X₂, X₃, X₄, X₅, X₆ and X₇ represents a sulfo group (including the    salts thereof) or a carboxyl group (including the salts thereof).-   (b) W preferably represents a substituted phenyl group, a    substituted or unsubstituted naphthyl group, or a substituted or    unsubstituted heterocyclic group (e.g., a pyrrole ring, a thiophene    ring, an imidazole ring, a thiazole ring, a benzothiazole ring, a    pyridine ring, or a pyridazine ring), and especially preferably a    substituted phenyl group (in particular, a phenyl group substituted    at the para-position), a substituted or unsubstituted -naphthyl    group, a pyridine ring, or a thiazole ring.-   (c) W₁₁ preferably represents an electron attracting group having a    Hammett's substitution constant σp value of 0.20 or more. An    electron attracting group having a σp value of 0.30 or more is    preferred, 0.45 or more is more preferred, and 0.60 or more is    especially preferred, but it is desired that the σp value does not    exceed 1.0. More specifically, W₁₁ preferably represents an acyl    group having from 2 to 20 carbon atoms, an alkyloxycarbonyl group    having from 2 to 20 carbon atoms, a nitro group, a cyano group, an    alkylsulfonyl group having from 1 to 20 carbon atoms, an    arylsulfonyl group having from 6 to 20 carbon atoms, a carbamoyl    group having from 1 to 20 carbon atoms, or a halogenated alkyl group    having from 1 to 20 carbon atoms, especially preferably represents a    cyano group, an alkyl-sulfonyl group having from 1 to 20 carbon    atoms, or an arylsulfonyl group having from 6 to 20 carbon atoms,    and most preferably a cyano group.-   (d) R₄₁ and R₄₂ each preferably represents a hydrogen atom, an alkyl    group, an aryl group, a heterocyclic group, an acyl group, an    alkylsulfonyl group, or an arylsulfonyl group, more preferably a    hydrogen atom, an alkyl group, an aryl group, or a heterocyclic    group, especially preferably a hydrogen atom, an aryl group having a    substituent, or a heterocyclic group having a substituent, and most    preferably a hydrogen atom or an aryl group having a substituent.    However, R₄₁ and R₄₂ do not represent a hydrogen atom at the same    time, and R₄₃ and R₄₁, or R₄, and R₄₂ may be bonded to each other to    form a 5- or 6-membered ring.-   (e) R₄₃ and R₄₄ each preferably represents a hydrogen atom, a    halogen atom, an alkyl group, an alkenyl group, an alkyl group, an    aralkyl group, an aryl group, a heterocyclic group, a cyano group, a    carboxyl group, a carbamoyl group, an alkoxycarbonyl group, an    aryloxycarbonyl group, a heterocyclic oxycarbonyl group, a hydroxyl    group, an amino group (including an alkylamino group, an arylamino    group, and a heterocyclic amino group), an acylamino group, a ureido    group, a sulfamoylamino group, an alkoxycarbonylamino group, an    aryloxycarbonylamino group, an alkylsulfonylamino group, an    arylsulfonylamino group, or a heterocyclic sulfonylamino group, and    each group may further be substituted.

R₄₃ more preferably represents a hydrogen atom, a halogen atom, an arylgroup, a heterocyclic group, a cyano group, a carboxyl group, acarbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, or aheterocyclic oxycarbonyl group, still more preferably a cyano group, acarboxyl group, a carbamoyl group, or an alkoxycarbonyl group, andespecially preferably a cyano group.

R₄₄ more preferably represents a hydrogen atom, a halogen atom, an alkylgroup, an alkenyl group, an alkynyl group, an aralkyl group, an arylgroup, a heterocyclic group, a hydroxyl group, an amino group (includingan alkylamino group, an arylamino group, and a heterocyclic aminogroup), an acylamino group, a ureido group, a sulfamoylamino group, analkoxy-carbonylamino group, an aryloxycarbonylamino group, analkylsulfonylamino group, an arylsulfonylamino group, or a heterocyclicsulfonyl amino group, still more preferably a hydrogen atom, a halogenatom, an alkyl group, an alkenyl group, an alkynyl group, an aralkylgroup, or an aryl group, and most preferably a methyl group.

-   (f) R₄₅ and R₄₆ each preferably represents a hydrogen atom, an alkyl    group, an aryl group, a heterocyclic group, an acyl group, an    alkylsulfonyl group, or an arylsulfonyl group, and more preferably a    hydrogen atom, an alkyl group, an aryl group, or a heterocyclic    group, especially preferably a hydrogen atom, an aryl group having a    substituent, or a heterocyclic group having a substituent, and most    preferably a hydrogen atom or an aryl group having a substituent    However, R₄₅ and R₄₆ do not represent a hydrogen atom at the same    time, and R₄₅ and R₄₆ may be bonded to each other to form a 5- or    6-membered ring.

Regarding combination of the preferred substituents of the dyestuffrepresented by formula (L-5), a compound wherein at least one of varioussubstituents is the above preferred group is preferred, a compoundwherein more substituents of various substituents are the abovepreferred groups is more preferred, and a compound wherein all thesubstituents are the preferred groups is most preferred.

The compound represented by formula (L-4) and/or (L-5) is preferably acompound represented by the following formula (L-4-1) and/or (L-5-1) forthe reason of capable of exhibiting more excellent performance.

In formula (L-4-1), R₁₁ and R₁₂ each represents an ionic hydrophilicgroup, especially preferably a sulfo group (including the saltsthereof), or a carboxyl group (including the salts thereof), and a sulfogroup is preferred above all; m and n each represents an integer of from1 to 3, especially preferably an integer of 1 or 2, and m and n eachmost preferably represents 1; W has the same meaning as W in formula(L-4), and the preferred examples are also the same; and X₁, X₂, X₃, X₄,X₅, X₆ and X₇ each has the same meaning as X₁, X₂, X₃, X₄, X₅, X₆ and X₇in formula (L-4), and the preferred examples are also the same.

In formula (L-5-1), R₁₁ and R₁₂ each represents an ionic hydrophilicgroup, especially preferably a sulfo group (including the saltsthereof), or a carboxyl group (including the salts thereof), and a sulfogroup is preferred above all; m and n each represents an integer of from1 to 3, especially preferably an integer of 1 or 2, and m and n eachmost preferably represents 1; W has the same meaning as W in formula(L-5), and the preferred examples are also the same; W₁₁ has the samemeaning as W₁₁ in formula (L-5), and the preferred examples are also thesame; and X₁, X₂, X₃, X₄, X₅, X₆ and X₇ each has the same meaning as X₁,X₂, X₃, X₄, X₅, X₆ and X₇ in formula (L-5), and the preferred examplesare also the same.

The specific examples of the azo dyes represented by formula (L-1) areshown below, but the invention is not limited thereto. The carboxylgroup, phosphono group and sulfo group in the following specificexamples may be in the state of salts, and the examples of counter ionsfor forming the salt include an ammonium ion, an alkali metal ion (e.g.,a lithium ion, a sodium ion, a potassium ion), and an organic cation(e.g., a tetramethylammonium ion, a tetramethylguanidinium ion, atetramethylphosphonium ion). Of these counter ions, the cases of anammonium ion, an organic cation and a lithium ion are preferred, and alithium ion is most preferred

It is preferred for the ink composition in the invention to contain thecounter ion.

A—N═N—B—N═N—C A B C (a-1)

(a-2)

(a-3)

(a-4)

(a-5)

(a-6)

(b-1)

(b-2)

(b-3)

(b-4)

(b-5)

(b-6)

(b-7)

(c-1)

(c-2)

(c-3)

(c-4)

(c-5)

(d-1)

(d-2)

(d-3)

(d-4)

(d-5)

(d-6)

(e-1)

(e-2)

(f-1)

(f-2)

(f-3)

(f-4)

(g-1)

(g-2)

(g-3)

(g-4)

(g-5)

(g-6)

(h-1)

(h-2)

(h-3)

(h-4)

(h-5)

(h-6)

(i-1)

(i-2)

(i-3)

(i-4)

(i-5)

(i-6)

(j-1)

(j-1)

(j-1)

(j-1)

(j-1)

(j-1)

(k-1)

(k-2)

(k-3)

(k-4)

(k-5)

(k-6)

(l-1)

(l-2)

(l-3)

(l-4)

(l-5)

(l-6)

(m-1)

(m-2)

(m-3)

(m-4)

(m-5)

(m-6)

(n-1)

(n-2)

(n-3)

(n-4)

(n-5)

(n-6)

(o-1)

(o-2)

(o-3)

(o-4)

(o-5)

(o-6)

In the invention, in addition to at least one compound represented byformula (L-1), a salt thereof, or a compound having a naphthalene ringsubstituted with at least one hydroxyl group and three or more azogroups, at least other water-soluble long wave dye L having a differentstructure is used in combination

By using a compound having a naphthalene ring substituted with at leastone hydroxyl group and three or more azo groups, an image excellent inimage fastness and free from blotting in preservation under a highhumidity condition can be obtained.

The more the number of azo groups of a compound, the higher is themolecular weight, so that the blotting of image can be restrained inpreservation under a high humidity condition, but the solubility in inkis liable to lower, and there is a case where the preservation stabilityof ink becomes a problem. To reconcile these points, the number of azogroups is preferably from 3 to 5.

It is preferred that a compound having a naphthalene ring substitutedwith at least one hydroxyl group and three or more azo groups has ahydrophilic group.

The examples of the hydrophilic groups include a sulfo group, a carboxylgroup, a phosphono group, an amino group, a nitro group, and aquaternary ammonium group. As the hydrophilic groups, a carboxyl group,a phosphono group, an amino group, a nitro group, and a sulfo group arepreferred, a carboxyl group and a sulfo group are especially preferred,and a sulfo group is most preferred from the viewpoint of increasingsolubility in an aqueous solvent.

The hydrophilic group may be in the form of a salt. In the examples ofions having counter charge to hydrophilic groups and forming salt (ionpair) (hereinafter referred to as a counter salt or a counter ion),ammonium, an alkali metal (e.g., lithium, sodium, potassium), an organiccation (tetramethylammonium, tetramethylguanidinium,tetramethyl-phosphonium) and the like are included. As the counter ions,each ion of ammonium, lithium, sodium and potassium are preferred, asodium ion and a lithium ion are more preferred, and a lithium ion ismost preferred.

A compound having a naphthalene ring substituted with at least onehydroxyl group and three or more azo groups is preferably a compoundselected from the compounds represented by formula (L-6), (L-6a), (L-7)or (L-8).

In addition to at least one compound represented by formula (L-1), asalt thereof, or a compound having a naphthalene ring substituted withat least one hydroxyl group and three or more azo groups, it ispreferred to use at least one compound different in structurerepresented by any of formulae (L-1) to (L-5) in combination, or acompound represented by any of formulae (L-1) to (L-5), and a compoundrepresented by any of formulae (L-6) to (L-8) in combination.Water-soluble long wave dyes L usable in combination are not especiallyrestricted so long as the above conditions of water-soluble long wavedye L are satisfied.

By the use of water-soluble long wave dye L different in structure incombination with the compound represented by formula (L-1), a blackimage having high density can be obtained and bronze glossiness at ahigh density part can be restrained as compared with the case where thecompound represented by formula (L-1) is used alone. The cause of theeffect is not clearly known, but it is presumed that by the use of thecompound represented by formula (L-1), which is a dye having anassociating property, and water-soluble long wave dye L different instructure in combination, the association of the compound represented byformula (L-1) is loosened in a degree of not impairing image fastness.

Not to impair image fastness, water-soluble long wave dye L to be usedin combination is preferably fast to light and ozone gas. Further, tolessen the change in hue at the time of deterioration of images by lightand ozone, it is preferred that the value of discoloring speed constantof water-soluble long wave dye L to be used in combination approximatesto that of the discoloring speed constant of the compound of formula(L-1). Specifically, the ratio of both values is more preferably in therange of from 0.5 to 2.0, but it is not restrictive thereto. Thediscoloring speed constant can be found with each of light fastness andozone-proofness according to the method disclosed in JP-A-2004-107638,paragraphs [0011] and [0012].

The blending ratio of the compound represented by formula (L-1) andwater-soluble long wave dye L to be used in combination, [additionamount of formula (L-1) (g)]/[addition amount of water-soluble long wavedye L used in combination (g)] is preferably from 0.3 to 100, morepreferably from 0.6 to 20, and still more preferably from 1.0 to 10.When the blending ratio is less than 0.3, the addition amount of formula(L-1) is not sufficient and there is a possibility that image fastnessis inferior, while when it is greater than 100, the addition amount ofthe dye to be used in combination is deficient, so that the effects ofimage density and restraint of bronze glossiness are not sometimessatisfactory.

In the invention, it is possible to use two or more compoundsrepresented by formula (L-1) in combination. In that case, it ispreferred to define a dye having the strongest associating property asthe compound represented by formula (L-1) and the other dyes aswater-soluble long wave dyes L to be used in combination in the methodof judging the associating property from the visible absorption spectra(described in paragraph [0035]) so as to be in the above blending ratio.

From the viewpoints of being fast to light and ozone gas and the valueof discoloring speed constant approximates to that of the compound offormula (L-1), water-soluble long wave dye L to be used in combinationis preferably selected from formulae (L-4), (L-5), (L-6), (L-6a), (L-7)and (L-8).

Formulae (L-4) and (L-5) and the preferred examples are described above.The compounds represented by formulae (L-4) and (L-5) can be preferablyused as the compound of formula (L-1), and as water-soluble long wavedye L to be used in combination with the compound represented by formula(L-4), the compound of formula (L-4) may be used (this is also appliedto the compound of formula (L-5)). As the dye to be used in combinationat this time, a dye having a smaller degree of an associating propertyis preferred.

When the compounds of formulae (L-4) and (L-5) are added aswater-soluble long wave dyes L to be used in combination, the differencein structure between the compound of formula (L-1) and water-solublelong wave dyes L is not especially restricted so long as the formulaeare satisfied, but it is preferred that the site of B in formula (L-1)differs. As an example, the combination of the compound of formula (L-4)and the compound of formula (L-5) is exemplified, but the invention isnot restricted thereto. Further, when two or more kinds of the compoundsof formula (L-4) are used in combination, it is preferred that thestructures of the site of W in formula (L-4) differ. When two or morekinds of the compounds of formula (L-5) are used in combination, it isalso preferred that the compounds differ in the structures of the siteof W similarly to the case of formula (L-4).

In formula (L-6), R₁₁ and R₁₂ each represents a hydrogen atom; a halogenatom; a cyano group; a carboxyl group; a sulfo group; a sulfamoyl groupthat may be substituted with an alkyl group or a phenyl group; aphosphoric acid group; a nitro group; an acyl group; a ureido group; analkyl group having from 1 to 4 carbon atoms that may be substituted witha hydroxyl group or an alkoxyl group having from 1 to 4 carbon atoms; analkoxyl group having from 1 to 4 carbon atoms or an acylamino group thatmay be substituted with a hydroxyl group, an alkoxyl group having from 1to 4 carbon atoms, a sulfo group, or a carboxyl group; E represents aphenyl group or a naphthyl group, which may be substituted with ahalogen atom; a cyano group; a carboxyl group; a sulfo group; asulfamoyl group that may be substituted with an alkyl group or a phenylgroup; a phosphoric acid group; a nitro group; an acyl group; a ureidogroup; an alkyl group having from 1 to 4 carbon atoms that may besubstituted with a hydroxyl group or an alkoxyl group having from 1 to 4carbon atoms; an alkoxyl group having from 1 to 4 carbon atoms or anacylamino group that may be substituted with a hydroxyl group, analkoxyl group having from 1 to 4 carbon atoms, a sulfo group or acarboxyl group; and n₁ represents 0 or 1.

The compound represented by formula (L-6) is preferably a compoundrepresented by the following formula (L-10).

In formula (L-10), R₁₃, R₁₄ and R₁₅ each represents a hydrogen atom; ahalogen atom; a cyano group; a carboxyl group; a sulfo group; asulfamoyl group that may be substituted with an alkyl group having from1 to 4 carbon atoms or a phenyl group; a phosphoric acid group; a nitrogroup; an acyl group; a ureido group; an alkyl group having from 1 to 4carbon atoms that may be substituted with a hydroxyl group or an alkoxylgroup having from 1 to 4 carbon atoms; an alkoxyl group having from 1 to4 carbon atoms or an acylamino group that may be substituted with ahydroxyl group, an alkoxyl group having from 1 to 4 carbon atoms, asulfo group, or a carboxyl group; and at least one of R₁₃, R₁₄ and R₁₅is a sulfo group or a carboxyl group; and n₁ is 0 or 1.

The specific examples of preferred compounds represented by formula(L-6) and the salts thereof are shown below, but the invention is notrestricted thereto. The following specific examples are shown in a freeacid structure, but of course the compounds may be used in the form ofan arbitrary salt.

The compound represented by formula (L-6) and the salts thereof aredisclosed in detail in JP-A-2005-220211, and the compounds shown in thesame patent can be preferably used.

In formula (L-6a), A represents the following formula (L-6a-1), and thesubstitution position of A is the m- or p-position to the azo group; R¹and R² each represents a hydrogen atom; a halogen atom; a cyano group; acarboxyl group; a sulfo group; a sulfamoyl group; anN-alkylaminosulfonyl group; an N-phenylaminosulfonyl group; a phosphogroup; a nitro group; an acyl group; a ureido group; an alkyl grouphaving from 1 to 4 carbon atoms that may be substituted with a hydroxylgroup or an alkoxyl group having from 1 to 4 carbon atoms; an alkoxylgroup having from 1 to 4 carbon atoms that may be substituted with ahydroxyl group, an alkoxyl group having from 1 to 4 carbon atoms, asulfo group, or a carboxyl group; or an acylamino group that may besubstituted with an alkoxyl group having from 1 to 4 carbon atoms, asulfo group, or a carboxyl group; R³ and R⁴ each represents a hydrogenatom; a halogen atom; a cyano group; a carboxyl group; a sulfo group; anitro group; an alkyl group having from 1 to 4 carbon atoms; a hydroxylgroup; or an alkoxyl group having from 1 to 4 carbon atoms that may besubstituted with an alkoxyl group having from 1 to 4 carbon atoms or asulfo group; and n represents 0 or 1.

In formula (L-6a-1), R⁵ represents a cyano group; a carboxyl group; analkyl group having from 1 to 4 carbon atoms; an alkoxycarbonyl grouphaving from 1 to 4 carbon atoms, or a phenyl group; R⁶, R⁷ and R⁸ eachrepresents a hydrogen atom; a halogen atom; a cyano group; a carboxylgroup; a sulfo group; a nitro group; an alkyl group having from 1 to 4carbon atoms; an alkoxyl group having from 1 to 4 carbon atoms that maybe substituted with a hydroxyl group, an alkoxyl group having from 1 to4 carbon atoms, or a sulfo group; or an acylamino group that may besubstituted with a hydroxyl group, an alkoxyl group having from 1 to 4carbon atoms, or a sulfo group.

The specific examples of preferred compounds represented by formula(L-6a) and the salts thereof are shown below, but the invention is notrestricted thereto. The following specific examples (Compound Nos. 1 to27) are shown in a free acid structure, but of course the compounds maybe used in the form of an arbitrary salt.

Cpd. No. Structural Formula 1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

The compound represented by formula (1-6a) and the salts thereof aredisclosed in detail in JP-A-2005-097912, and the compounds shown in thesame patent can be preferably used.

In formula (L-7), G and J each represents a phenyl group or a naphthylgroup that may be substituted, or a 5- or 6-membered aromaticheterocyclic group bonding to the azo group via a carbon atom, and eachof G and J contains at least one or more carboxyl group(s) or sulfogroup(s); one of X and Y represents a hydroxyl group, and the otherrepresents an amino group; and l₂, m₂ and n₂ each represents 1 or 2.

The compound represented by formula (L-7) is preferably a compoundrepresented by the following formula (L-11).

In formula (L-11), G and J each represents a phenyl group or a naphthylgroup that may be substituted, or a 5- or 6-membered aromaticheterocyclic group bonding to the azo group via a carbon atom, and eachof G and J contains at least one or more carboxyl group(s) or sulfogroup(s); a and b each represents a single bond, the bonding position ofbond a is the 2- or 3-position, and the bonding position of bond b isthe 6- or 7-position; one of X and Y represents a hydroxyl group, andthe other represents an amino group; and l₃, m₃ and n₃ each represents 0or 1.

In formula (L-11), G and J each preferably represents a phenyl group ora naphthyl group that may be substituted with a substituent containingat least one or more carboxyl group(s) and/or sulfo group(s). Theexamples of the substituents substituted on G and J include a halogenatom; a hydroxyl group; an amino group; a carboxyl group; a sulfo group;a nitro group; an alkyl group; an alkoxyl group; an acyl group; a phenylgroup; a ureido group; an alkyl group substituted with a hydroxyl group,an alkoxyl group, a sulfo group, or a carboxyl group; an alkoxyl groupsubstituted with a hydroxyl group, an alkoxyl group, a sulfo group, or acarboxyl group; a phenyl group that may be substituted with a carboxylgroup or a sulfo group; and an amino group substituted with an alkylgroup or an acyl group.

In formula (L11), it is preferred that G and J each has a sulfo group atthe o-position to the azo group, and represents a phenyl group that maybe substituted with a nitro group, an alkoxyl group, or a sulfo group

The specific examples of preferred compounds represented by formula(L-7) and the salts thereof are shown below, but the invention is notrestricted thereto. The following specific examples are shown in a freeacid structure, but of course the compounds may be used in the form ofan arbitrary salt.

The compound represented by formula (L-7) and the salts thereof aredisclosed in detail in JP-A-2004-285351, and the compounds shown in thesame patent can be preferably used.

In formula (L-8), R₂₁ represents a phenyl group having a substituent, ora naphthyl group having a substituent; R₂₂ represents a phenylene grouphaving a substituent, or a naphthylene group having a substituent; R₂₃represents a 5- to 7-membered heterocyclic group having at least onedouble bond and a substituent; and the substituents in R₂₁, R₂₂ and R₂₃are each selected from the group consisting of OH, SO₃H, PO₃H₂, CO₂H,NO₂, NH₂, an alkyl group having from 1 to 4 carbon atoms, an alkyl grouphaving a substituent, an alkoxyl group having from 1 to 4 carbon atoms,an alkoxyl group having a substituent, an amino group, an amino grouphaving a substituent, and a phenyl group having a substituent.

The compound represented by formula (L-8) is preferably a compoundrepresented by the following formula (L-9) and the salts thereof.

In formula (L-9), R₃₁ to R₃₉ each represents a group selected from thegroup consisting of H, OH, SO₃H, PO₃H₂, CO₂H, NO₂, and NH₂.

The specific examples of preferred compounds represented by formula(L-8) or (L-9) and the salts thereof are shown below, but the inventionis not restricted thereto. The following specific examples are shown ina free acid structure, but of course the compounds may be used in theform of an arbitrary salt.

The compounds represented by formula (L-8) or (L-9) and the saltsthereof are disclosed in detail in WO 03/106572 and JP-A-2005-2271, andthe compounds shown in the same patents can be preferably used.

In the invention, the later-described water-soluble short wave dye S canbe used as a color correction dye.

Water-soluble Short W Dye S:

Water-soluble short wave dye S that can be used in the invention has themaximum of an absorption spectrum (the absorption maximum: λmax) in anaqueous solvent of from 400 to 540 nm. The half value width of theabsorption spectra is preferably from 90 to 200 nm, and a dye capable ofachieving broad absorption is preferred.

The absorption spectrum of water-soluble short wave dye S is anabsorption spectrum measured with a single compound. That is, when anabsorption spectrum in an aqueous solvent is measured, water-solubleshort wave dye S in the invention means to show the physical propertiessuch as the desired absorption maximum and half value width not bycombining a plurality of compounds but to show these physical propertiesby a single compound. Incidentally, it is apparent in the invention thatas water-soluble short wave dyes S (hereinafter also referred to as“short wave dye S”), compounds having structures different from eachother may be used in combination so long as they satisfy the absorptionspectra.

Having such absorption characteristics, short wave dye S can absorblights in a broad range from blue to green that is liable to beinsufficient with the absorption spectra of water-soluble long wave dyeL such as a dis-azo dye or a tris-azo dye, and has preferred absorptioncharacteristics as a color correction dye.

The absorption maximum of short wave dye S is preferably from 400 to 540nm, and especially preferably from 460 to 500 nm.

The half value width at the absorption maximum of short wave dye S ispreferably from 100 to 180 nm, and especially preferably from 110 to 160nm.

It is preferred for short wave dye S in the invention not to have adissociable phenolic hydroxyl group that is present in ordinarydyestuffs, which structure ensures preferred properties, for example,variation in color tone dependent upon the image-receiving material usedis little, and reactivity with oxidizing gas, e.g., ozone in the air, islow and excellent in an anti gas property.

Here, “a dissociable phenolic hydroxyl group” means a dissociablehydroxyl group that is substituted with an aryl group. The aryl groupmay be substituted with other substituent.

It is preferred for short wave dye S in the invention to have from 2 to6 azo groups in one molecule, which structure enhances a colordeveloping property, and provides images having good fixing ability dueto the broadened plane of dyestuff.

Further, the number of azo groups is more preferably from 4 to 6 in onemolecule in respects of a color developing property and fixing ability.

Short wave dyes S are not especially restricted so long as they have thephysical properties defined in the invention and capable of dissolvingthe foregoing problem, and a polyazo dye represented by the followingformula can be exemplified:(D)_(n)-Y

In the formula, D represents a dye residue of chromophore consisting offrom 1 to 3 azo groups conjugated to each other, and from 3 to 4aromatic rings having 20 or more π electrons in total, and n is 1 or 2.When n is 1, Y represents a hydrogen atom, and when n is 2, Y representsa divalent linking group. The aromatic rings composing chromophore maybe heterocyclic rings or hydrocarbon rings, but preferably hydrocarbonrings. In the case where the aromatic rings composing chromophore form acondensed ring, the number of π electrons on the aromatic rings is thenumber of π electrons of the condensed ring as a whole, e.g., the numberof π electrons of a naphthalene ring is 10. The divalent linking grouprepresented by Y is an alkylene group, an arylene group, a heterocyclicresidue, —CO—, —SO_(n)— (where n is 0, 1 or 2), —NR— (where R representsa hydrogen atom, an alkyl group, or an aryl group), —O—, or a divalentlinking group combining these linking groups, and these groups mayfurther have a substituent, e.g., an alkyl group, an aryl group, analkoxyl group, an amino group, an acyl group, an acylamino group, ahalogen atom, a hydroxyl group, a carboxyl group, a sulfamoyl group, acarbamoyl group, a sulfonamido group, etc. As the especially preferredexamples of linking groups, —NH—CO—NH—, —NH—CS—NH—, and a grouprepresented by the following formula can be exemplified.

In the specification of the invention, an alkyl group means a straightchain, branched, cyclic (including monocyclic, polycyclic, and a bridgedform and spiro in the case of polycyclic), or monovalent saturatedhydrocarbon group obtained by combining these alkyl groups, and includesa cycloalkyl group, a cycloalkylalkyl group, etc., and further includesa substituted alkyl group in the case where an alkyl group may besubstituted.

In the specification of the invention, an alkenyl group means a straightchain, branched, cyclic (including monocyclic, polycyclic, and a bridgedform and spiro in the case of polycyclic), or monovalent unsaturatedhydrocarbon group obtained by combining these alkenyl groups having oneor more carbon-carbon double bond exclusive of aromatic groups, andfurther includes a substituted alkenyl group in the case where analkenyl group may be substituted.

In the specification of the invention, for example, a substituted alkylgroup means an alkyl group whose hydrogen atom is substituted with asubstituent, and the substituent may be one or more, and one or morehydrogen atoms may be substituted. This is also applied to a substitutedaryl group.

In the formula, X represents a hydroxyl group, a sulfo group, an alkoxylgroup, an aryloxy group, an amino group (including an alkylamino groupand an arylamino group), an alkylsulfenyl group, or an arylsulfenylgroup, and each group may further have a substituent.

As short wave dye S, for example, commercially available C.I. Direct Red84, C.I. Direct Brown 106, and C.I. Direct Brown 202 are useful, andC.I. Direct Red 84 that ran be used for the correction of tone of manyblack dyes and excellent in a color developing property and fastness isespecially useful.

The examples of short wave dyes S preferably used in the invention areshown below in a free acid structure, but of course the compounds may beused in the form of an arbitrary salt.

As preferred counter cations, an alkali metal (e.g., lithium, sodium,potassium), ammonium, and an organic cation (e.g., pyridinium,tetramethylammonium, guadinium) can be exemplified.

A SB-1

SB-2

SB-3

SB-4

SB-5

SB-6

A X SB-7

—NHC₂H₄OH SB-8

—NHC₂H₄OH SB-9

—NHC₂H₄OH SB-10

—N(C₂H₄OH)₂) SB-11

—N(C₂H₄OH)₂) SB-12

—NHC₂H₄OH

A SB-13

SB-14

SB-15

Of these short wave dyes S, C.I. Direct Red 84 (sodium salt of theExemplified Compound SB-2), and C.T. Direct Brown 106 (sodium salt ofthe Exemplified Compound SB-14) are preferred for capable of availableas commercial dye, and C.I. Direct Red 84 excellent in a colordeveloping property, fastness and a fixing property is especiallyuseful.

As the examples of the counter salts of C.I. Direct Red 84 and C.I.Direct Brown 106, ammonium, an alkali metal (e.g., lithium, sodium,potassium), and an organic cation (e.g., tetramethylammonium,tetramethylguadinium, tetramethyl-phosphonium) can be exemplified. Asthe counter salts, ammonium, lithium, sodium, and potassium arepreferred, and sodium and lithium are more preferred. Sodium salts arecommercially available as above and preferred. It is known that the useof lithium salts as counter salts results in the improvement of thesolubility of dyes in water, so that very preferred from the respects ofstability and precipitation by aging in the state of ink.

Incidentally, short wave dyes S other than commercially available dyescan be easily synthesized with commercially available materialsaccording to the synthesizing route of C.I. Direct Red 84 or C.I. DirectBrown 106 as described in Color Index, Vol. 4, published by The Societyof Dyers and Colourists.

The black ink composition in the invention contains from 0.1 to 4 mass %of short wave dye S, preferably from 0.5 to 3.0 mass %, and especiallypreferably from 1.0 to 2.5 mass %, but the amount can be arbitrarilychanged as desired. (In this specification, mass ratio is equal toweight ratio.)

Other Dyes:

Further, other dyes can also be used in combination in the invention foradjusting the tone and the like of a black ink composition in the rangenot greatly impairing light fastness and ozone-proofness.

As yellow dyes, aryl or heteryl azo dyes having, e.g., phenols,naphthols, anilines, pyrazolones, pyridones or open chain type activemethylene compounds as the coupling component; azomethine dyes having,e.g., open chain type active methylene compounds as the couplingcomponent; methine dyes, such as benzylidene dyes and monomethine oxonoldyes; and quinone dyes, such as naphthoquinone dyes and anthraquinonedyes are exemplified. Besides these kinds of dyes, quinophthalone dyes,nitro-nitroso dyes, acridine dyes and acridinone dyes are exemplified.These dyes may be dyes that present yellow not until after a part of thechromophore has been dissociated, and the counter cations in that casemay be inorganic cations, e.g., an alkali metal and ammonium, or may beorganic cations, e.g., pyridinium and quaternary ammonium salt, or thecounter cations may be polymer cations having these cations as thepartial structure.

As magenta dyes, aryl or heteryl azo dyes having, e.g., phenols,naphthols or anilines as the coupling component; azomethine dyes having,e.g., pyrazolones or pyrazolo-triazoles as the coupling component;methine dyes, e.g., arylidene dyes, styryl dyes, merocyanine dyes, andoxonol dyes; carbonium dyes, e.g., diphenylmethane dyes,triphenylmethane dyes, and xanthene dyes; quinone dyes, e.g.,naphthoquinone, anthraquinone and anthrapyridone; and condensationpolycyclic dyestuffs, e.g., dioxazine dyes are exemplified. These dyesmay be dyes that present magenta not until after a part of thechromophore has been dissociated, and the counter cations in that casemay be inorganic cations, e.g., alkali metal and ammonium, or may beorganic cations, e.g., pyridinium and quaternary ammonium salt, or thecounter cations may be polymer cations having these cations as thepartial structure.

As cyan dyes, azomethine dyes, e.g., indoaniline dyes and indophenoldyes; polymethine dyes, e.g., cyanine dyes, oxonol dyes and merocyaninedyes; carbonium dyes, e.g., diphenylmethane dyes, triphenylmethane dyesand xanthene dyes; phthalocyanine dyes; anthraquinone dyes; aryl orheteryl azo dyes having, e g., phenols, naphthols or anilines as thecoupling component; and indigo thioindigo dyes are exemplified. Thesedyes may be dyes that present cyan not until after a part of thechromophore has been dissociated, and the counter cations in that casemay be inorganic cations, e.g., alkali metal and ammonium, or may beorganic cations, e.g., pyridinium and quaternary ammonium salt) or thecounter cations may be polymer cations having these cations as thepartial structure.

Black dyes, e.g., polyazo dye, can also be used.

Water-soluble dyes, such as direct dyes, acid dyes, food dyes, basicdyes, and reactive dyes can also be used in combination. Preferred dyesof such dyes are listed below, but the invention is not restrictedthereto:

-   C.I. Direct Red 2, 4, 9, 11, 23,26, 31, 37, 39, 62, 63, 72, 75, 76,    79, 80, 81, 83, 84, 87, 89, 92, 95, 111, 173, 184, 207, 211, 212,    214, 218, 219, 223, 224, 225, 226, 227, 232, 233, 240, 241, 242,    243, 247, 254-   C.I. Direct Violet 7, 9, 47, 48, 51, 66, 90, 93, 94, 95, 98, 100,    101-   C.I. Direct Yellow 4, 8, 9, 11, 12, 27, 28, 29, 33, 35, 39, 41, 44,    50, 53, 58, 59, 68, 86, 87, 93, 95, 96, 98, 100, 106, 108, 109, 110,    120, 130, 132, 142, 144, 157, 161, 163-   C.I. Direct Blue 1, 10, 15, 22, 25, 55, 67, 68, 71, 76, 77, 78, 80,    84, 86, 87, 90, 98, 106, 108, 109, 151, 156, 158, 159, 160, 168,    189, 192, 193, 194, 199, 200, 201, 202, 203, 207, 211, 213, 214,    218, 225, 229, 236, 237, 244, 248, 249, 251, 252, 264, 270, 280,    288, 289, 290, 291-   C.I. Direct Black 9, 17, 19, 22, 32, 51, 56, 62, 69, 77, 80, 91, 94,    97, 108, 112, 113, 114, 117, 118, 121, 122, 125, 132, 146, 154, 166,    168, 173, 199-   C.I. Acid Red 1, 8, 35, 42, 52, 57, 62, 80, 81, 82, 87, 94, 111,    114, 115, 118, 119, 127, 128, 131, 143, 144, 151, 152, 154, 158,    186, 245, 249, 254, 257, 261, 263, 266, 289, 299, 301, 305, 336,    337, 361, 396, 397-   C.I. Acid Violet 5, 34, 43, 47, 48, 90, 103, 126-   C.I. Acid Yellow 17, 19, 23, 25, 39, 40, 42, 44, 49, 50, 61, 64, 76,    79, 110, 127, 135, 143, 151, 159, 169, 174, 190, 195, 196, 197, 199,    218, 219, 222, 227-   C.I. Acid Blue 9, 25, 40, 41, 62, 72, 76, 78, 80, 82, 87, 92, 106,    112, 113, 120, 127:1, 129, 138, 143, 175, 181, 185, 205, 207, 220,    221, 230, 232, 247, 249, 258, 260, 264, 271, 277, 278, 279, 280,    288, 290, 326-   C.I. Acid Black 7, 24, 29, 48, 52:1., 172-   C.I. Reactive Red 3, 6, 13, 17, 19, 21, 22, 23, 24, 29, 35, 37, 40,    41, 43, 45, 49, 55, 63, 106, 107, 112, 113, 114, 126, 127, 128, 129,    130, 131, 137, 160, 161, 174, 180-   C.I. Reactive Violet 1, 3, 4, 5, 6, 7, 8, 9, 16, 17, 22, 23, 24, 26,    27, 33, 34-   C.I. Reactive Yellow 2, 3, 13, 14, 15, 17, 18, 23, 24, 25, 26, 27,    29, 35, 37, 41, 42-   C.I. Reactive Blue 2, 3, 5, 7, 8, 10, 13, 14, 15, 17, 18, 19, 21,    25, 26, 27, 28, 29, 38, 82, 89, 158, 182, 190, 203, 216, 220, 244-   C.I. Reactive Black 4, 5, 8, 14, 21, 23, 26, 31, 32, 34-   C.I. Basic Red 12, 13, 14, 15, 18, 22, 23, 24, 25, 27, 29, 35, 36,    38, 39, 45, 46-   C.I. Basic Violet 1, 2, 3, 7, 10, 15, 16, 20, 21, 25, 27, 28, 35,    37, 39, 40, 48-   C.I. Basic Yellow 1, 2, 4, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28,    29, 32, 36, 39, 40-   C.I. Basic Blue 1, 3, 5, 7, 9, 22, 26, 41, 45, 46, 47, 54, 57, 60,    62, 65, 66, 69, 71-   C.I. Basic Black 8

Besides the above dyes, the dyes disclosed in the following patents canalso be used in combination, but the invention is not restrictedthereto: WO 01/48090, WO 04/087815, WO 02/090441, WO 03/027185, WO04/085541, JP-A-2003-321627, JP-A-2002-332418, JP-A-2002-332419, WO02/059216, WO 02/059215, WO 04/087814, WO 00/58407, Japanese Patents3558211, 3558212, 3558213, JP-A-2004-323605, and WO 04/104108.

The black ink composition in the invention contains at least two kindsof water-soluble dyes as colorants, and the total amount of thecolorants preferably accounts for from 0.5 to 12 wt % in the totalweight of the black ink composition, more preferably from 3.0 to 10.0 wt%, and especially preferably from 5.0 to 8.0 wt %.

When the total amount of the dyes contained in the black ink compositionis 0.5 wt % or more, and when an image is recorded on a recording mediumwith this ink composition, sufficiently satisfactory color developmentand high image density can be obtained.

When the total amount of the dyes contained in the black ink compositionis 12 wt % or less, the coefficient of viscosity of the ink compositioncan be adjusted to a desired value, the ejection amount of the inkcomposition from the ink jet head can be stabilized, and clogging of theink jet head can be prevented.

Water-miscible organic solvents that can be used in the ink compositionof the invention are materials having functions of a drying preventive,an osmosis accelerator, and a wetting agent, and water-miscible organicsolvents having a high boiling point are used. The specific examples ofsuch compounds are disclosed in JP-A-2004-331871, paragraphs [0419] to[0423].

Of water-miscible organic solvents, alcohol-based solvents areespecially preferably used in the invention. It is also preferred in theink composition of invention to contain to contain water-miscibleorganic solvents having a boiling point of 150° C. or higher.

These water-miscible organic solvents are preferably contained in atotal amount of from 5 to 60 mass % in the ink composition, andespecially preferably from 10 to 45 mass %.

For the purpose of enhancing the ejection stability of the inkcomposition of the invention, printing quality, and durability ofimages, additives such as a surfactant, a drying preventive, an osmosisaccelerator, urea-based additives, a chelating agent, an ultravioletabsorber, an antioxidant, a viscosity adjustor, a surface tensionadjustor, a dispersant, a dispersion stabilizer, an antiseptic, amildewproofing agent, an anticorrosion, a pH adjustor, a defoamingagent, a polymer material, an acid precursor, etc., as disclosed inJP-A-2004-331871 can be used by arbitrary selection. The preferred useamount of these additives is as disclosed in JP-A-2004-331871.

In addition to the above components, the black ink composition in theinvention can further contain one or more additives selected from thegroup consisting of a blotting preventive, a bronzing improver, and anozone-proofness improver, if necessary.

Blotting Preventive:

As a blotting preventive, betaine surfactants are exemplified. Thebetaine surfactants disclosed in JP-A-2005-111699, paragraphs [0017] to[0044] can be arbitrarily selected and used.

Bronzing Improver:

A bronzing improver for use in the invention has function to weaken orget rid of the bronzing phenomenon that occurs when solid printing isperformed with an ink set containing a black ink composition, forexample, aromatic compounds having a carboxyl group or salts thereof areexemplified as bronzing improvers.

As the aromatic compounds having a carboxyl group or salts thereof, thecompounds disclosed in JP-A-2004-263155, paragraph [0044] can bearbitrarily selected and used.

The total use amount of the aromatic compound having a carboxyl groupand/or a salt thereof is determined according to the kind of thearomatic compound having a carboxyl group and/or a salt thereof, thekinds of dyes, and the kind of solvent components.

Further, as other bronzing improvers, colorless and water-soluble planecompounds having more than ten delocalization π electrons in onemolecule are preferably used.

As the water-soluble plane compounds, the compounds disclosed inJP-A-2005-105261, paragraphs [0012] to [0026] can be arbitrarilyselected and used.

The content of these bronzing improvers is preferably from 0.1 to 10 wt% based on the total weight of the black ink composition, and morepreferably the range of from 0.5 to 5 wt %.

Ozone-proofness Improver:

An ozone-proofness improver is a compound having function of restrainingthe oxidation of dyes and, for example, thiol-based compounds,amidine-based compounds, carbazide-based compounds, hydrazide-basedcompounds, guanidine-based compounds are exemplified.

Thiol-based Compounds:

Thiol-based compounds for use in the invention are compounds having anSH group, and aromatic thiol and aliphatic thiol are preferred, e.g., acompound represented by the following formula (B) is preferred.R₁₀—SH  (B)wherein R₁₀ represents an alkyl group, an aryl group, or a heterocyclicgroup.

R₁₀ is described below.

As the allyl group, preferably an alkyl group having from 1 to 1 2carbon atoms, and more preferably from 1 to 6 carbon atoms.

As the aryl group, preferably an aryl group having from 6 to 18 carbonatoms, and more preferably from 6 to 10 carbon atoms.

As the heterocyclic group, a furyl group, a pyridyl group, a pyrimidylgroup, a pyrrolyl group, a pyrrolinyl group, a pyrrolidyl group, adioxolyl group, a pyrazolyl group, a pyrazolinyl group, a pyrazolidylgroup, an imidazolyl group, an oxazolyl group, a thiazolyl group, anoxadiazolyl group, a triazolyl group, a thiadiazolyl group, a pyrylgroup, a pyridyl group, a piperidyl group, a dioxanyl group, a morpholylgroup, a pyridazyl group, a pyrazyl group, a piperazyl group, a triazylgroup, a trithianyl group, etc., are exemplified.

The substituents represented by R₁₀ include substituents whose hydrogenatoms are further substituted with other arbitrary substituents. Suchsubstituents include a carboxyl group, an oxo group, an amino group, anamino acid residue (preferably having from 2 to 8 carbon atoms), anammonium group, a hydroxyl group, a thiol group, an alkoxyl group(preferably having from 1 to 12 carbon atoms), an acylamino group(preferably having from 1 to 12 carbon atoms, the carboxyl group and theamino group may be substituted), a carbamoyl group, etc., areexemplified, and two or more of these substituents may be substituted onthe same molecule.

As the synthesizing method of the compound represented by formula (B),e.g., by the reaction of applicable aryl Grignard's reagent and singlesulfur, thiol wherein R₁₀ is an aryl group is obtained, and by thereaction of applicable halogenated alkyl and sodium hydrogensulfide orthiourea, thiol wherein R₁₀ is an aryl group is obtained. Amidine-basedcompounds:

Amidine-based compounds for use in the invention are compounds having astructure in which —C(═NH)—NH₂ group (an amidino group) is bonded to thecarbon atom of the group containing a carbon atom, and one or morehydrogen atoms of the —C(═NH)—NH₂ group may be substituted withsubstituents.

An amidine-based compound represented by the following formula (C) ispreferably used.

In formula (C), R₅₁, R₅₂, R₅₃ and R₅₄ each represents a hydrogen atom,an alkyl group, an aryl group, or a heterocyclic group, and when R₅₁contains a nitrogen atom, the nitrogen atom is not bonded to C shown inthe formula.

The alkyl group is an alkyl group preferably having from 1 to 12 carbonatoms, and more preferably from 1 to 6 carbon atoms.

The aryl group is an aryl group preferably having from 6 to 18 carbonatoms, and more preferably from 6 to 10 carbon atoms.

As the heterocyclic group, a fill group, a pyridyl group, a pyrimidylgroup, a pyrrolyl group, a pyrrolinyl group, a pyrrolidyl group, adioxolyl group, a pyrazolyl group, a pyrazolinyl group, a pyrazolidylgroup, an imidazolyl group, an oxazolyl group, a thiazolyl group, anoxadiazolyl group, a triazolyl group, a thiadiazolyl group, a pyrylgroup, a pyridyl group, a piperidyl group, a dioxanyl group, a morpholylgroup, a pyridazyl group, a pyrazyl group, a piperazyl group, a triazylgroup, a trithianyl group, etc., are exemplified.

The hydrogen atoms of the substituents represented by R₅₁ to R₅₄ mayfurther be substituted with arbitrary other substituents. As suchsubstituents, a halogen atom, e.g., chlorine, a nitro group, an aminogroup, a carboxyl group, a carbamoyl group, an amidino group, an aryloxygroup (the aryl moiety may further be substituted with any substituentsenumerated here), etc., are exemplified, and two or more of thesesubstituents may be substituted on the same molecule. The hydrogen atomsof the above amino group, carbamoyl group, and amidino group may besubstituted with the alkyl group, aryl group or heterocyclic grouprepresented by R₅₁ to R₅₄.

The amidine-based compound may take the form of a salt, such ashydrochloride.

The compound represented by formula (C) can be obtained at least by theprocess of acting ammonia on the applicable hydrochloride of iminoether.Carbazide-based compounds:

Carbazide-based compounds for use in the invention are carbazide andderivatives thereof, and a compound represented by the following formula(D) is used.R₅₅R₅₆NCONHNR₅₇R₅₈  (D)

In formula (D), R₅₅ to R₅₈ each represents a hydrogen atom or an organicgroup.

As the organic group, the organic groups represented by R₅₁ to R₅₄ aboveare preferred

The substituents represented by R₅₅ to R₅₈ include substituents thehydrogen atoms of which are further substituted with other arbitrarysubstituents. As such substituents, in addition to those capable ofbeing substituted with R₅₁ to R₅₄ exemplified above, —NHCONHNR₅₉R₆₀(where R₅₉ and R₆₀ each represents an organic group, and the preferredexamples are the same as R₅₁ to R₅₄) is preferably exemplified. In theinvention, —NHCONHNR₅₉R₆₀ is called a carbazide structure. Thecarbazide-based compounds for use in the invention have preferably 2 ormore (more preferably from 2 to 6) carbazide structures in the samemolecule.

The carbazide-based compound represented by formula (D) can be obtainedspecifically by condensation reaction of applicable isocyanate ordiisocyanate, urea derivatives, etc., with hydrazine compoundsrepresented by NH₂NR₅₇R₅₈ (where R₅₇ and R₅₈ are the same as above).

Hydrazide-based Compounds:

Hydrazide-based compounds for use in the invention are hydrazide andderivatives thereof, and a compound represented by the following formula(E) is used.R₆₁CONHNR₆₂R₆₃  (E)

In formula (E), R₆₁, R₆₂ and R₆₃ each represents a hydrogen atom, ahydrazino group, or an organic group; R₆₁ and R₆₂ or R₆₃ may be bondedto form a ring.

As the organic group, the organic groups exemplified in R₅₁ to R₅₄ informula (C) are preferred.

The substituents represented by R₆₁ to R₆₃ include substituents thehydrogen atoms of which are further substituted with other arbitrarysubstituents. As such substituents, in addition to those capable ofbeing substituted with R₅₁ to R₅₄ exemplified above, an acyl group, acyano group, an alkoxyl group, an aralkyloxy group, a benzoyloxy group,—NHCONHNR₆₄R₆₅ (where R₆₄ and R₆₅ each represents an organic group, andthe preferred examples are the same as R₅₁ to R₅₄) is preferablyexemplified. In the invention, —NHCONHNR₆₄R₆₅ is called a hydrazidestructure. The hydrazide-based compounds for use in the invention havepreferably 2 or more (more preferably from 2 to 6) hydrazide structuresin the same molecule.

The hydrazide-based compound represented by formula (E) can be obtainedspecifically by condensation reaction of applicable acid derivatives oracid anhydrides such as carboxylic acid ester or acid halide, etc., witha hydrazine compound represented by NH₂NR₆₂R₆₃ (where R₆₂ and R₆₃ arethe same as above).

Of the ozone-proofness improvers, guanidine-based compounds areespecially preferred. Guanidine-based compounds are described in detailbelow.

Guanidine-based Compounds:

Guanidine-based compounds for use in the invention are compounds havingan N—C(═N)—N structure.

As guanidine-based compounds, a compound represented by the followingformula (F) is preferred.

In formula (F), R₇₁, R₇₂, R₇₃ and R₇₄ each represents a hydrogen atom,an alkyl group, an alkoxyl group, an aryl group, a heterocyclic group,or an amino group; and R₇₅ represents a hydrogen atom, an alkyl group,an alkoxyl group, an aryl group, or a heterocyclic group. These alkylgroup, alkoxyl group, aryl group, heterocyclic group, or amino group maybe substituted or may not substituted.

The alkyl group is an alkyl group preferably having from 1 to 12 carbonatoms, and especially preferably from 1 to 6 carbon atoms.

The alkoxyl group is an alkoxyl group preferably having from 1 to 12carbon atoms, and especially preferably from 1 to 6 carbon atoms.

The aryl group is an aryl group preferably having from 6 to 18 carbonatoms, and especially preferably from 6 to 10 carbon atoms.

As the heterocyclic group, a furyl group, a pyridyl group, a pyrimidylgroup, a pyrrolyl group, a pyrrolinyl group, a pyrrolidyl group, adioxolyl group, a pyrazolyl group, a pyrazolinyl group, a pyrazolidylgroup, an imidazolyl group, an oxazolyl group, a thiazolyl group, anoxadiazolyl group, a triazolyl group, a thiadiazolyl group, a pyrylgroup, a pyridyl group, a piperidyl group, a dioxanyl group, a morpholylgroup, a pyridazyl group, a pyrazyl group, a piperazyl group, a triazylgroup, a trithianyl group, etc., are exemplified.

The hydrogen atoms of the alkyl group, alkoxyl group, aryl group orheterocyclic group represented by R₇₁ to R₇₅ may further be substitutedwith arbitrary other substituents. As such substituents, a halogen atom,e.g., chlorine, a nitro group, an amino group, a carboxyl group, ahydroxyl group, a carbamoyl group, an amidino group, a guanidino group,an aryloxy group (the aryl moiety may further be substituted with anysubstituents enumerated here), etc., are exemplified, and two or more ofthese substituents may be substituted on the same molecule. The hydrogenatoms of the above amino group, carbamoyl group, amidino group andguanidino group may be substituted with the alkyl group, alkoxyl group,aryl group or heterocyclic group represented by R₇₁ to R₇₅.

The hydrogen atoms of the amino group represented by R₇₁ to R₇₄ mayfurther be substituted with the alkyl group, alkoxyl group, aryl groupor heterocyclic group represented by R₇₁ to R₇₅.

The guanidine-based compounds may be in the form of a salt or a metalcomplex, for example, hydrochloride, nitrate, phosphate, sulfamate,carbonate, acetate, etc., are exemplified.

The compound represented by formula (F) can be obtained at least by theprocess of acting ammonia on the applicable hydrochloride of iminoether.

The guanidine-based compounds may be polymers having an N—C(═N)—Nstructure. As such polymers, compounds containing a repeating unitrepresented by the following formula (F-a), (F-b) or (F-c), but theinvention is not restricted thereto. The compounds containing therepeating unit may be oligomers. The compounds containing the repeatingunit represented by formula (F-c) may be monomers. These compounds arepreferably salts with acids.

In formula (F-a), R₇₅ has the same meaning as above; R₇₆ represents anyof R₇₁, R₇₂, R₇₃ and R₇₄, and n of R₇₅ and R₇₆ may be the same ordifferent; and n7 represents an integer of 2 or more, preferably from 2to 30, and more preferably from 2 to 15. The compound containing therepeating unit represented by formula (F-a) may be a homopolymer, or maybe a copolymer with other repeating unit, e.g., azetidinium, etc. Theterminal structure can be arbitrarily selected, but a hydrogen atom, analkyl group, an alkoxyl group, an aryl group, a heterocyclic group or anamino group is preferred.

In formula (F-b), R₇₅ and R₇₆ have the same meaning as above, and l7 ofR₇₅ and R₇₆ may be the same or different. l7 is an integer of 2 or more,preferably from 2 to 10, and more preferably from 2 to 5. m7 is aninteger of 1 or more, preferably from 1 to 6, and more preferably from 1to 3. The compound containing the repeating unit represented by formula(F-b) may be a homopolymer, or may be a copolymer with other repeatingunit, e.g., azetidinium, etc. The terminal structure can be arbitrarilyselected, but a hydrogen atom, an alkyl group, an alkoxyl group, an arylgroup, a heterocyclic group or an amino group is preferred.

In formula (F-c), R₇₅ has the same meaning as above; R₇₇ has the samemeaning as R₇₁ or R₇₂; R₇₆ has the same meaning as R₇₃ or R₇₄, and p7 ofR₇₅, R₇₆ and R₇₇ maybe be the same or different. p7 is an integer of 1or more, preferably from 1 to 10, and more preferably from 1 to 5. Thecompound containing the repeating unit represented by formula (F-c) maybe a homopolymer, or may be a copolymer with other repeating unit, e.g.,azetidinium, etc. The terminal structure can be arbitrarily selected,but a hydrogen atom, an alkyl group, an alkoxyl group, an aryl group, aheterocyclic group or an amino group is preferred.

These various compounds can be used alone or in combination as theozone-proofness improver, and the use amount is preferably from 0.1 to10 mass % in the black ink composition.

The coefficient of viscosity of the black ink composition in theinvention is preferably from 1 to 20 mPa·s, more preferably from 2 to 15mPa·s, and especially preferably from 2 to 10 mPa·s. When thecoefficient of viscosity exceeds 20 mPa·s, the fixing speed of arecorded image lowers and the ejecting property also lowers. When theviscosity is less than 1 mPa·s, a recorded image blots and grade isdeteriorated. The coefficient of viscosity is measured at 25° C. Thecoefficient of viscosity is adjusted with the viscosity adjustor. Theaddition amount of a water-miscible organic solvent is, in the case ofink jet recording, preferably from 5 to 70 mass % to the black inkcomposition, and more preferably from 10 to 60 mass %. Water-miscibleorganic solvent can be used in combination of two or more kinds.

A measuring method of the coefficient of viscosity of a liquid isdescribed in detail in JIS Z8803, but it can be measured easily with acommercially available viscometer. For instance, B type viscometer and Etype viscometer (manufactured by Tokyo Keiki Co) are known as a rotarytype. In the invention, viscosity was measured with an oscillating typeMV-100A-L type (manufactured by YAMAICHI ELECTRONICS Co., Ltd.) at 25°C.

The black ink composition in the invention preferably has surfacetension of from 20 to 50 mN/m, and more preferably from 20 to 40 mN/m.

Surface tension means both dynamic surface tension and static surfacetension, and both are measured at 25° C. When the surface tension ishigher than 50 mN/m, ejection stability lowers, blotting occurs at colormixing time and the qualities of printed characters conspicuouslydeteriorate such that whiskers appear. When the surface tension of inkis lower than 20 mN/m, printing failure sometimes occurs due to adhesionof the ink to the surface of hardware. Surfactants can be used for theadjustment of surface tension, and the above-described surfactants canbe used.

As measuring methods of static surface tension, a capillary rise method,a dropping method and a suspension lug method are known. A verticalpanel method is used in measuring static surface tension in theinvention.

When a part of a thin panel of glass or platinum is immersed in a liquidand hung vertically, the surface tension of the liquid works downwardalong the length where the liquid and the panel are in contact. Staticsurface tension can be measured with equilibrating this force by upwardforce.

As measuring methods of dynamic surface tension, a oscillation jetmethod, a meniscus dropping method, and a maximum bubble pressure methodas described in Shin-Jikken Kagaku Koza (New Experimental Chemistry),Vol. 18, “Kaimen to Colloid (Interface and Colloid)”, pp. 69 to 90,Manizen Co. (1977) are known, further, as disclosed in JP-A-3-2064, aliquid film breaking method is known. In the invention, a bubblepressure differential pressure method is used for the measurement ofdynamic surface tension. The principle of the measurement and measuringmethod are described below.

When bubbles are formed in a stirred and homogenized solution, newair-liquid interface is formed and surfactant molecules in the solutiongather on the surface of the solution at a constant velocity. When abubble rate (generating velocity of bubbles) is changed, if generatingvelocity slows down, more molecules of the surfactant gather on thesurfaces of bubbles, thus the maximum bubble pressure just beforebreaking of bubbles becomes small and the maximum bubble pressure(surface tension) to the bubble rate can be detected. As the preferredmeasuring method of dynamic surface tension, a method of generatingbubbles in a solution with two probes, large and small, measuring thedifferential pressure of two probes at the state of maximum bubblepressure, and computing the dynamic surface tension can be exemplified.

The conductivity of the black ink composition in the invention ispreferably from 0.01 to 10 S/m, and particularly preferably from 0.05 to5 S/m. The conductivity is measured at 25° C. By making the conductivitythe above range, image stability can be secured.

The conductivity can be measured by an electrode method usingcommercially available saturated potassium chloride.

The conductivity can be controlled primarily by the ion concentration inan aqueous solution. When the concentration of salt is high,desalinization can be performed through an ultrafiltration membrane.When conductivity is controlled by the addition of salts, control can bedone by the addition of various organic and inorganic salts.

As the inorganic salts, inorganic compounds, e.g., potassium halide,sodium halide, sodium sulfate, potassium sulfate, sodiumhydrogensulfate, potassium hydrogensulfate, sodium nitrate, potassiumnitrate, sodium hydrogencarbonate, potassium hydrogencarbonate, sodiumphosphate, sodium monohydrogenphosphate, boric acid, potassiumdihydrogen-phosphate, sodium dihydrogenphosphate, etc., and organiccompounds, e.g., sodium acetate, potassium acetate, potassium tartrate,sodium tartrate, sodium benzoate, potassium benzoate, sodiump-toluenesulfonate, potassium caccharinate, potassium phthalate, sodiumpicolinate, etc., can be used.

The conductivity can also be controlled by the selection of theabove-described additives.

The pH of the black ink composition in the invention is preferably from7 to 9, and more preferably from 7 to 8. When the pH is less than 7, thesolubility of dye lowers and nozzles are liable to generate clogging,while when the pH is higher than 9, a waterproof property is liable todeteriorate. pH can be measured with commercially available test paper,or can be measure by an electrode method with saturated potassiumchloride.

The pH of the black ink composition can be adjusted with the pHadjustor.

It is possible to use the black ink composition in the invention invarious image recordings for its high image durability. As the materialsfor imaging, for example, utilization for photographic photosensitivematerials, utilization for heat transfer materials, utilization forheat-sensitive/pressure-sensitive materials, and utilization for ink jetrecording are possible, and of these uses, utilization as black inkcomposition for ink jet recording is most preferred.

Manufacturing methods of ink compositions for ink jet recording aredisclosed in detail in each of JP-A-5-148436, JP-A-5-295312,JP-A-7-97541, JP-A-7-82515, JP-A-7-118584, and JP-A-2004-331871, andthese methods can be used in the manufacture of the ink composition inthe invention.

As the recording papers and recording films that are printing mediapreferably used in the invention, those disclosed in JP-A-2004-331871(paragraphs [0503] to [0627]) are preferably used.

In the manufacture of ink, ultrasonic vibration can be included in adissolution process of additives such as dyes as disclosed inJP-A-2004-331871.

In manufacturing ink in the invention, a process of removal of residuathat are solids content by filtration carried out after preparation ofink is important. The filtration process is also disclosed inJP-A-2004-331871

The black ink composition in the invention can be used not only forforming a monochrome image but also a full color image. For forming afull color image, an ink set preferably contains at least the inkcompositions of yellow, magenta and cyan, and a plurality of inkcompositions that are the same in hue and different in density can alsobe used with respective colors. Further, red, green, blue, andintermediate tone ink composition such as violet can also be used.

The examples of dyes as the colorants contained in the ink compositionthat can be preferably used in the ink set in the invention are shownbelow, but the invention is by no means restricted thereto.

Yellow Dye:

As yellow dyes, those disclosed in WO 05/075573, JP-A-2004-83903(paragraphs [0024] to [0062]), JP-A-2003-277661 (paragraphs [0021] to[0050]), JP-A-2003-277662 (paragraphs [0042] to [0047]),JP-A-2003-128953 (paragraphs [0025] to [0076]), JP-A-200341160(paragraphs [0028] to [00641]), U.S. Patent Application U.S.2003/0213405 (paragraph [0108]), and a compound represented by thefollowing formula (Y-1) are exemplified.

In formula (Y-1), G represents a heterocyclic group, and n represents aninteger of from 1 to 3. When n is 1, R, X, Y, Z, Q and G each representsa monovalent group. When n is 2, R, X, Y, Z, Q and G each represents amonovalent or divalent substituent, and at least one represents adivalent substituent. When n is 3, R, X, Y, Z, Q and G each represents amonovalent, divalent or trivalent substituent, and at least tworepresent a divalent substituent or at least one represents a trivalentsubstituent.

The compound represented by formula (Y-1) is preferably a compoundrepresented by any of the following formulae (Y-2), (Y-3), (Y4), (Y-5)and (Y-6).

In formula (Y-2), R₁, R₂, X₁, X₂, Y₁, Y₂, Z₁ and Z₂ each represents amonovalent group; G represents an atomic group to constitute a 5- to8-membered nitrogen-containing heterocyclic ring; M represents ahydrogen atom or a cation; and m₁ represents an integer of from 0 to 3.

In formula (Y-3), R₁, R₂, R₁₁, R₁₂, X₁, X₂, Z₁ and Z₂ each represents amonovalent group; L₁ represents a divalent linking group; G₁ and G_(2 a)each represents an atomic group to constitute a 5- to 8-memberednitrogen-containing heterocyclic ring; M represents a hydrogen atom or acation; and m₂₁ and m22 each represents an integer of from 0 to 3.

In formula (Y-4), R₁, R₂, R₁₁, R₁₂, X₁, X₂, Y₁ and Y₂ each represents amonovalent group; L₂ represents a divalent linking group; G₁ and G₂ eachrepresents an atomic group to constitute a 5- to 8-memberednitrogen-containing heterocyclic ring; M represents a hydrogen atom or acation; and m₃₁ and m₃₂ each represents an integer of from 0 to 3.

In formula (Y-5), R₁₁, R₁₂, X₁, X₂, Y₁, Y₂, Z₁ and Z₂ each represents amonovalent group; L₃ represents a divalent linking group; G₁ and G₂ eachrepresents an atomic group to constitute a 5- to 8-memberednitrogen-containing heterocyclic ring; M represents a hydrogen atom or acation; and m₄₁ and m₄₂ each represents an integer of from 0 to 3.

In formula (Y-6), R₁, R₂, R₁₁, R₁₂, Y₁, Y₂, Z₁ and Z₂ each represents amonovalent group; L₄ represents a divalent linking group; G₁ and G₂ eachrepresents an atomic group to constitute a 5- to 8-memberednitrogen-containing heterocyclic ring; M represents a hydrogen atom or acation; and m₅₁ and m₅₂ each represents an integer of from 0 to 3.

In formulae (Y-2), (Y-3), (Y-4), (Y-5) and (Y-6), thenitrogen-containing heterocyclic ring constituted of G, G₁ and G₂ ispreferably an S-triazine ring.

The specific examples of the compounds represented by formulae (Y-1),(Y-2), (Y-3), (Y-4), (Y-5) and (Y-6) (Exemplified Dyes 1 to 26) areshown below, but the dyes used in the invention are not restricted tothese compounds.

The structures of the following specific examples are shown in the formof a free acid, but of course the compounds may be used in the form ofan arbitrary salt.

As preferred counter cations, an alkali metal (e.g., lithium, sodium,potassium), ammonium, and an organic cation (e.g., pyridinium,tetramethylammoniun, guanidinium) can be exemplified.

Magenta Dye:

As magenta dyes, heterocyclic azo dyes are preferred, and the compoundsdisclosed in WO 02/83795 (pages 35-55), WO 02/83662 (pages 27-42),JP-A-2004-149560 (paragraphs [0046] to [0059]), JP-A-2004-149561(paragraphs [0047] to [0060]), and an azo dyestuff represented by thefollowing formula (M-1) are exemplified.

In formula (M-1), A represents the residue of a 5-membered heterocyclicdiazo component A-NH₂; B₃₁ and B₃₂ each represents —CR₈₁═ or —CR₈₂═, oreither one represents a nitrogen atom and the other represents —CR₈₁═ or—CR₈₂═; R₈₃ and R₈₄ each represents a hydrogen atom, an aliphatic group,an aromatic group, a heterocyclic group, an acyl group, analkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, analkylsulfonyl group, an arylsulfonyl group, or a sulfamoyl group, andeach group may further have a substituent; R₈₁ and R₈₂ each represents ahydrogen atom, a halogen atom, an aliphatic group, an aromatic group, aheterocyclic group, a cyano group, a carboxyl group, a carbamoyl group,an alkoxycarbonyl group, an aryloxycarbonyl group, an acyl group, ahydroxyl group, an alkoxyl group, an aryloxy group, a silyloxy group, anacyloxy group, a carbamoyl group, a heterocyclic oxy group, analkoxycarbonyloxy group, an aryloxycarbonyloxy group, an alkylaminogroup, an arylamino group, a heterocyclic amino group, an acylaminogroup, a ureido group, a sulfamoylamino group, an alkoxycarbonylaminogroup, an aryloxycarbonylamino group, an alkylsulfonylamino group, anarylsulfonylamino group, an aryloxycarbonylamino group, a nitro group,an alkylthio group, an arylthio group, an alkylsulfonyl group, anarylsulfonyl group, an alkylsulfinyl group, an arylsulfinyl group, asulfamoyl group, a sulfo group, or a heterocyclic thio group, and eachgroup may further be substituted, and R₈₁ and R₈₃, or R₈₃ and R₈₄ may bebonded to form a 5- or 6-membered ring; a and e each represents an alkylgroup, an alkoxyl group, or a halogen atom, when a and e both representan alkyl group, the total number of carbon atoms constituting the alkylgroup is 3 or more, and they may be further substituted; b, c and d eachhas the same meaning as R₈₁ and R², and a and b, or e and d, may becondensed with each other, provided that formula (M-1) has at least oneionic hydrophilic group.

A represents the residue of a 5-membered heterocyclic diazo componentA-NH₂. As the examples of the hetero atoms of the 5-memberedheterocyclic ring, N, O and S are exemplified. The 5-memberedheterocyclic ring is preferably a nitrogen-containing 5-memberedheterocyclic ring, and an aliphatic ring, an aromatic ring, or otherheterocyclic ring may be condensed with the heterocyclic ring.

The preferred examples of the heterocyclic rings represented by Ainclude a pyrazole ring, an imidazole ring, a triazole ring, a thiazolering, an isothiazole ring, a thiadiazole ring, a benzothiazole ring, abenzoxazole ring, and a benzisothiazole ring. Each heterocyclic ring mayfurther have a substituent. Of these heterocyclic rings, a pyrazolering, an imidazole ring, an isothiazole ring, a thiadiazole ring, abenzothiazole ring, and a triazole ring are preferred.

The azo dyestuff represented by the formula (M-1) is preferablyrepresented by the following formula (M-2).

In formula (M-2), Z₁₁ represents an electron attracting group having aHammett's substitution constant σp value of 0.20 or more; Z₁₂ representsa hydrogen atom, an acyl group, an aliphatic group, an aromatic group,or a heterocyclic group; R₈₁, R₈₂, R₈₃, R₈₄, a, b, c, d and e each thesame meaning as in formula (M-1); and Q₁₁ represents a hydrogen atom, analiphatic group, an aromatic group, or a heterocyclic group. Each ofZ₁₁, Z₁₂ and Q₁₁ may further have a substituent, provided that formula(M-2) has at least one ionic hydrophilic group.

The specific examples of azo dyestuffs are shown below, but theinvention is not restricted thereto.

Cpd. X R¹ R² R³ R⁴ a b c d e a-1 CH₃ CN CH₃ H

CH₃ H SO₃H H C₂H₅ a-2 ″ CONH₂ H ″

iPr ″ ″ ″ iPr a-3 ″ H CH₃

″ ″ ″ ″ ″ ″ a-4 ″ ″ ″ ″

C₂H₅ ″ ″ ″ C₂H₅ a-5 ″ ″ ″ ″

″ ″ CH₃ SO₃H ″

Cpd. X R¹ R² R³ R⁴ a b c d e b-1 —SCH₃ CN CH H

CH₃ H SO₃H H C₂H₅ b-2

CONH₂ H ″

iPr ″ ″ ″ iPr b-3

H CH₃

″ ″ ″ ″ ″ ″ b-4

″ ″ ″

C₂H₅ ″ ″ ″ C₂H₅ b-5 —SCH₃ ″ ″ ″

″ ″ CH₃ SO₃H ″

Cpd. X R¹ R² R³ R⁴ a b c d e c-1 5-Cl CN CH₃ H

CH₃ H SO₃H H C₂H₅ c-2 5,6-diCl CONH₂ H ″

iPr ″ ″ ″ iPr c-3 5-CH₃ H CH₃

″ ″ ″ ″ ″ ″ c-4 6-Cl ″ ″ ″

C₂H₅ ″ ″ ″ C₂H₅ c-5 5,6-diCl ″ ″ ″

″ ″ CH₃ SO₃H ″

Cpd. X Q R¹ R² R³ R⁴ a b c d e d-1

CN CH₃ H

CH₃ H SO₃H H C₂H₅ d-2 t-Bu ″ CONH₂ H ″

iPr ″ ″ ″ iPr d-3 ″ ″ H CH₃

″ ″ ″ ″ ″ ″ d-4 ″ ″ ″ ″ ″

C₂H₅ ″ ″ ″ C₂H₅ d-5 ″ ″ ″ ″ ″

″ ″ CH₃ SO₃H ″

Cpd. X Q R¹ R² R³ d-6 t-Bu

H CH₃

d-7 ″ ″ ″ ″ ″ d-8 ″ ″ ″ ″ ″ d-9 ″

″ ″

d-10 ″ ″ ″ ″ ″ Cpd. R⁴ a b c d e d-6

CH₃ H SO₃H H iPr d-7

″ ″ ″ ″ OCH₃ d-8

″ ″ CH₃ SO₃H Cl d-9

C₂H₅ ″ ″ ″ C₂H₅ d-10

iPr ″ SO₃H ″ iPr

Cpd. Q B₁ B₂ R³ d-11

N C—CH₃ H d-12

″

″ d-13 ″ C—H N ″ d-14

C—H N

d-15 ″ N

″ Cpd. R⁴ a b c d e d-11

C₂H₅ H CH₃ SO₃H C₂H₅ d-12 ″ ″ ″ ″ ″ ″ d-13

iPr ″ SO₃H H iPr d-14

CH₃ ″ ″ ″ C₂H₅ d-15 ″ ″ ″ ″ ″ ″

Cpd. X Q R¹ R² R³ R⁴ a b c d e d-16 t-Bu

H CH₃

C₂H₅ H CH₃ SO₃H C₂H₅ d-17 ″

″ ″

″ ″ ″ ″ ″ d-18 ″ ″ ″ ″

″ ″ ″ ″ ″ d-19 ″

″ ″

″ ″ ″ ″ ″ ″ d-20 ″

″ ″

″ ″ ″ ″ ″ ″Cyan Dye:

As phthalocyanine dye is preferred as cyan dye, and associatingphthalocyaninc dyes are preferred. As the associating phthalocyaninedyes, those having an associating group are preferred. The associatinggroup means a group at least having a bonding site (Or a functionalgroup) capable of hydrogen bonding between molecules at least in thegroup. The bonding site can be present one or more in one group. As thebonding sites, a hydroxyl group, an amino group, an amido bond, an oxidebond, etc., are exemplified, and hydrogen bonding is formed between thesame kind or different kinds. The associating group may be one capableof hydrogen bonding between a phthalocyanine dye and an arbitraryadditive.

For reducing the reactivity with ozone that is an electrophilic agent,it is preferred to make oxidation potential 1.0 V (vs SCE) or nobler bypartially substituting the carbon atom of a phthalocyanine skeleton witha hetero atom, e.g., azaphthalocyanine, or by introducing an electronattracting group into a phthalocyanine skeleton. The nobler, the morepreferred is the oxidation potential. The oxidation potential is morepreferably 1.1 V (vs SCE) or nobler, and especially preferably 1.15 V(vs SCE) or nobler.

As associating phthalocyanine dyes, those disclosed in WO 02/60994, WO03/811, WO 03/62324, JP-A-2003-213167, JP-A-2004-75986,JP-A-2004-323605, JP-A-2004-315758, JP-A-2004-315807 andJP-A-2005-179469 are exemplified.

Besides the above patents, phthalocyanine dyes can be synthesizedaccording to JP-A-2004-315729,JP-A-200541856 and JP-A-2004-323511.Further, starting materials, dye intermediates, and synthesis route arenot restricted thereto.

The ink set in the invention can also be used for uses other than inkjet recording. For example, the ink set can be used as materials fordisplay image, image-forming materials of interior decoration, andimage-forming materials of outdoor decoration as disclosed inJP-A-2004-331871, paragraphs [0727] to [0731].

Besides the above dyes, the dyes disclosed in the following patents canalso be preferably used in ink composition of each color:JP-A-10-130557, JP-A-9-255906, JP-A-6-234944, JP-A-7-97541, EP 982371,WO 00/43450, WO 00/43451, WO 00/43452, WO 00/43453, WO 03/106572, WO03/104332, JP-A-2003-238862, JP-A-2004-83609, JP-A-2002-302619,JP-A-2002-327131, JP-A-2002-265809, WO 01/48090, WO 04/087815, WO02/00-441, WO 03/027185, WO 04/085541, JP-A-2003-321627,JP-A-2002-332418, JP-A-2002-332419, WO 02/059216, WO 02/059215, WO04/087814, WO 04/046252, WO 04/046265, Japanese Patent 3479444, U.S.Pat. No. 6,652,637B, WO 03/106572, WO 03/104332, WO 00/58407, JapanesePatent 3558211, Japanese Patent 3558212, Japanese Patent 3558213,JP-A-2004-285351, JP-A-2004-323605, and WO 04/104108.

Recording Method:

The recording method in the invention is to adhere the ink compositionof the invention to a recording material. The preferred recording methodin the invention is an ink jet recording method of performing recordingby ejecting the droplets of the ink composition onto a recording mediumby imparting energy to the ink composition to form an image on knownimage-receiving materials as materials to be recorded, that is, planepaper and resin coat paper, e.g., special paper for ink jet recording,films, electrophotographic common paper, napkin, glass, metal, ceramics,etc., as disclosed in JP-A-8-169172, JP-A-8-27693, JP-A-2-276670,JP-A-7-276789, JP-A-9-323475, JP-A-62-238783, JP-A-10-153989,JP-A-10-217473, JP-A-10-235995, JP-A-10-337947, JP-A-10-217597, andJP-A-10-337947. The description in JP-A-2003-306623, paragraphs [0093]to [0105] can be applied to the ink jet recording method in theinvention.

In forming an image, polymer latex compounds may be used in combinationfor the purpose of providing glossiness and a waterproof property, andimproving a weather resisting property. The time of applying polymerlatex compounds to an image-receiving material may be any time before,after, or at the same time with the addition of colorants, accordinglythe plate of addition may be in image-receiving paper, in ink, or may beused as a liquid material of a polymer latex alone.

Specifically, the methods disclosed in JP-A-2002-166638,JP-A-2002-121440, JP-A-2002-154201, JP-A-2002-144696, JP-A-2002-080759,JP-A-2002-187342 and JP-A-2002-172774 can be preferably used.

Recording paper and recording film for use in ink jet printing with theink of the invention are described below. The supports in recordingpaper and recording film comprise chemical pulp, e.g., LBKP, NBKP, etc.,mechanical pulp, e.g., GP, POW, RMP, TMp, CTMP, CMP, CGP, etc., andwastepaper pulp, e.g., DIP, etc., and manufactured by adding variousadditives, according to necessity, e.g., a conventionally known pigment,a binder, a sizing agent, a fixing agent, a cationic agent, and a paperstrength increasing agent, and made with various paper machines, e.g.,Fourdrinier machine and cylinder paper machine. Other than thesesupports, synthetic paper and a plastic film sheet can be used assupports. The thickness of a support is preferably from 10 to 250 μm andweight is from 10 to 250 g/m². An ink-receiving layer and a back coatlayer may be directly provided on a support, or an ink-receiving layerand a back coat layer may be provided after providing size press or ananchor coat layer with starch and polyvinyl alcohol. A support may besubjected to flattening treatment with calendering apparatus, e.g.,machine calender, TG calender or soft calender. In the invention assupports, paper and plastic film both surfaces of which are laminatedwith polyolefin (e.g., polyethylene, polystyrene, polyethyleneterephthalate, polybutene and copolymers thereof) are more preferablyused. It is preferred to add white pigments (c.g., titanium oxide, zincoxide) or toning dyes (e.g., cobalt blue, ultramarine, neodymium oxide)to polyolefin.

An ink-receiving layer provided on a support contains a pigment and anaqueous binder. The pigment is preferably a white pigment The examplesof white pigments include white inorganic pigments, e.g., calciumcarbonate, kaolin, talc, clay, diatomaceous earth, synthetic amorphoussilica, aluminum silicate, magnesium silicate, calcium silicate,aluminum hydroxide, alumina, lithopone, zeolite, barium sulfate, calciumsulfate, titanium dioxide, zinc sulfide, zinc carbonate, etc., andorganic pigments, e.g., styrene-based pigments, acrylic-based pigments,urea resins melamine resins, etc. As white pigments contained in anink-receiving layer, porous inorganic pigments are preferred, andsynthetic amorphous silica having a large pore area is especiallypreferred. As synthetic amorphous silica, both of silicic anhydridemanufactured by a dry manufacturing method and hydrous silicic acidmanufactured by a wet manufacturing method can be used, but it isespecially preferred to use hydrous silicic acid.

In the recording method of the invention, methods of ink jet recordingare not restricted, and the ink or ink set of the invention can be usedin known systems, for example, an electrical charge controlling systemof making use of electrostatic induction force and ejecting inkdroplets, a system of using ink jet heads of forming ink droplets bymechanical deformation of electrostrictive elements, a drop on demandsystem (a pressure pulse system) of utilizing vibratory pressure ofpiezo-elements, an acoustic ink jet system of converting electric signalto acoustic beam and irradiating ink, and ejecting ink droplets bymaking use of the radiation pressure, and a thermal ink jet system ofheating ink to thereby generate bubbles, and ejecting ink droplets byutilizing the generated pressure. Ink jet recording systems include asystem of ejecting a great number of minute volumes of ink droplets ofso-called photo-ink of low density, a system of improving image qualityby using a plurality of inks having substantially the same hue anddifferent densities, and a system of using colorless and transparentink.

EXAMPLE

The invention will be described with reference to examples, but theinvention is by no means restricted thereto.

Manufacture of Ink Stock Solution:

To 50 g of dye Black-6 was added 850 g of ultrapure water (specificresistance value: 18 MΩ·cm or more), and the mixture was stirred byheating at 60 to 65° C. for 1 hour with heating. After the dye wasthoroughly dissolved, the temperature was lowered to room temperature,and 100 g of 2-pyrrolidone as a viscosity reducing agent, and 1.0 g ofPROXEL XL2 as an antiseptic were added to the solution. After stirringfor 10 minutes, the solution was filtered rough a microfilter having anaverage pore size of 0.2 μm under reduced pressure to prepare an inkstock solution.

Preparation of Black Ink:

After adding ultrapure water (specific resistance value: 18 MΩ·cm ormore) to the following components to make 100%, each mixture was stirredby heating at 30 to 40° C. for 1 hour. The resulted solution was thenfiltered through a microfilter having an average pore size of 0.25 μmunder reduced pressure to prepare each black ink solution. In Table 1below, the numerical value of each component is shown in wt % taking themass of the ink composition as 100%, and “the rest” that shows theamount of water means the amount making 100% in total with thecomponents other than water.

TABLE 1 B-1 B-2 B-3 B-4 B-5 B-6 B-7 B-8 B-9 B-10 Black-1 4 4 4 3 3 3 6Black-2 3 2 6 Black-3 2 3 3 6 Black-4 2 Black-5 3 Black-7 3 Black-6 Inkstock solution 30 Glycerol 10 10 10 10 10 10 10 10 10 10 Triethyleneglycol 2 2 2 2 2 2 2 2 2 2 TEGmBE 8 8 8 8 8 8 8 8 8 8 Sarfinol 465 (*1)1 1 1 1 1 1 1 1 1 1 Urea 5 3 3 3 3 3 3 3 3 3 1,2-Hexanediol 3 3 3 3 3 33 3 3 3 Bronzing inhibitor I 1 PROXEL XL2 (*2) 0.3 0.3 0.3 0.3 0.3 0.30.3 0.3 0.3 0.3 Water The rest The rest The rest The rest The rest Therest The rest The rest The rest The rest Unit: wt % (*1) Manufactured byAir Products and Chemical, Inc. (*2) Manufactured by AbesiaWater-soluble Long Wave Dye L Represented by Formula (L-1):

Water-soluble Long Wave Dye L Represented by Formula (L-8):

Water-soluble Long Wave Dye L Represented by Formula (L-7):

Water-soluble Long Wave Dye L Represented by Formula (L6):

Water-soluble Short Wave Dye S:

Water-soluble Long Wave Dye L Represented by Formula (L-6a):

Example 1

These black inks were filled in black ink cartridges of Ink Jet PrinterPM-A700 (manufactured by SEIKO EPSON CORPORATION). A gray image whosedensity changed stepwise from R:0, G:0, B:0 to R:255, G:255, B:255(hereinafter referred to as step pattern) was made with imaging softwarePhotoshop (manufactured by Adobe Systems Incorporated), printed in“black” mode, and an image printed with black ink alone was obtained. Asthe image-receiving sheet, photographic paper (glossy paper)(manufactured by SEIKO EPSON CORPORATION) was used.

Evaluation:

-   1) The hue was evaluated by visually observing gray tone in each    printed density in gray step pattern. The hue that shows preferred    gray tone in each density is graded A, the hue where density of    losing gray balance here and there is found is graded B, and the hue    where almost all the densities lose gray balance is graded C.-   2) Regarding image density, Dvis of a black solid image (image data,    R:0, G:0, B:0 part) was measured with densitometer X-rite 310.

The case where Dvis is 2.4 or more is graded A, 2.3 or more and lessthan 2.4 is graded B, and the case where Dvis is less than 2.3 is gradedC.

-   3) Regarding preservation stability of image, evaluations of the    following 4) and 5) were performed with a gray printed sample. In    evaluation of image preservation stability, the density of step    pattern was measured with densitometer X-rite 310 loading Status A    Filter, and the change in density was measured with the point near    Dvis=1.0 being the reference point.-   4) Regarding light fastness, after finding the reflection spectrum    at 380 to 730 nm by the measurement of density Ci at the maximum    absorption wavelength just after printing with Spectroeye    (manufactured by Gretag Macbeth), the image was irradiated with a    xenon lamp (85,000 lux) for 10 days with a weather meter    (manufactured by Atlas). After that, the reflection spectrum was    again found by measuring density Cf at the maximum absorption    wavelength, and light fastness was evaluated by finding the residual    rate of dye [(Cf/Ci)×100].

The case where the residual rate of dye is 80% or more is graded A, thecase of from 70 to 80% is graded B, and the case of less than 70% isgraded C.

-   5) Regarding ozone-proofness, after finding the reflection spectrum    at 380 to 730 nm by the measurement of density Ci at the maximum    absorption wavelength just after printing with Spectroeye    (manufactured by Gretag Macbeth), the image was exposed to ozone gas    in a box set at ozone gas concentration of 5 ppm for 170 hours.    After that, the reflection spectrum was again found by measuring    density Cf at the maximum absorption wavelength, and ozone-proofness    was evaluated by finding the residual rate of dye [(Cf/Ci)×100].

The ozone gas concentration in the box was set with an ozone gas monitor(model OZG-EM-01, manufactured by APPLICS).

The case where the residual rate of dye is 80% or more is graded A, thecase of from 70 to 80% is graded B, and the case of less than 70% isgraded C.

-   6) Regarding the hue balance in the deterioration of image    (hereinafter referred to as discoloration balance), CIEL*a*b* was    measured with Spectroeye (manufactured by Gretag Macbeth) before and    after evaluations 4) and 5). ΔEa*b* was found from the value before    exposure L_(i)*a_(i)*b_(i)* and the value after exposure    L_(f)*a_(f)*b_(f)* according to the following expression, and the    discoloration balance was evaluated on the basis of the following    criteria    ΔEa*b*=[(a _(i) *−a _(f)*)²+(b _(i) *−b _(f)*)²]^(1/2)    Criteria of Evaluation:-   A: ΔEa*b* is smaller than 20 in both tests of 4) and 5).-   B: ΔEa*b* is larger than 20 in either one test, or both of 4) and    5).-   7) Regarding bronzing evaluation, black solid images were printed on    photographic paper CRISPIA (high glossy paper) (manufactured by    SETKO EPSON CORPORATION) on three conditions of 20° C. 40% RH,    35° C. 60% RH, and 35° C. 80% RH, and the images were allowed to    stand overnight on the same conditions. Bronzing (metallic    glossiness of the surfacc of the print) was evaluated by visual    observation on the basis of the following criteria.    Criteria of Evaluation:-   Grade A: Bronze glossiness is not observed at all.-   Grade B: Bronze glossiness is slightly observed in one condition of    three environmental conditions.-   Grade C: Bronze glossiness is slightly observed in two or more    conditions of three environmental conditions, and bronze glossiness    is clearly observed in one or more environmental conditions.-   8) Regarding image blotting of black ink under high humidity    condition, a checkered image having a line width of 0.2 mm and an    interval between lines of 0.2 mm was made with imaging software    Photoshop (manufactured by Adobe Systems Incorporated). A    black-and-white checkered image sample comprising lines in black    (R:0, R:0, B:0) and intervals between lines in white (R:255, G;255,    B:255) was formed, and blotting of the image after being allowed to    stand on the conditions of 25° C. 90% RH for 7 days was visually    judged.

An image having no blotting in the white area of the checker is gradedA, an image showing thickening of the line of the checker a little isgraded B, and an image where the black dye clearly blotted on the whitearea is graded C.

The results obtained are shown in Table 2 below.

TABLE 2 Light Ozone Discoloration Black Ink Hue Density FastnessProofness Balance Bronzing Blotting of Image B-1 B A A A A A A B-2 B A AA A A A B-3 B A A A A A A B-4 B A A A A A A B-5 B A A A A A A B-6 B A AA A A A B-7 A A A A A A A B-8 (Comparison) B B A A A A A B-9(Comparison) B B B B A B A B-10 (Comparison) B C B B A A A

As compared with the black inks (B-8, B-9, B-10) manufactured with thecompound of formula (L-1) alone, the black ink compositions in theinvention using water-soluble long wave dye L in addition to thecompound of formula (L-1) shows that the density in black solid part ishigh without deteriorating discoloration balance, and bronze glossinessis restrained. It was found that by using water-soluble short wave dye Sin addition to water-soluble long wave dye L, preferred black hue couldbe obtained.

When the same tests were carried out except for changing image-receivingsheets, almost the same results as in Table 2 were obtained. As theimage-receiving sheets, Kassai (Photo Finish Pro, manufactured by FujiPhoto Film Co., Ltd.), Kassai (Photo Finish Advance, manufactured byFuji Photo Film Co., Ltd.) double weight Hi, photographic paper CRISPIA(high glossy, manufactured by SEIKO EPSON CORPORATION), photographicpaper (glossy, manufactured by SEIKO EPSON CORPORATION), ProfessionalPhoto Paper (manufactured by Canon Inc.), Super Photo Paper(manufactured by Canon Inc.), and Photolike QP (photographic imagequality, manufactured by KONICA MINOLTA HOLDINGS, INC.) super doubleweight, were used.

Example 2

Preparation of Each Ink Composition:

Each ink composition was prepared by stirring at room temperature for 30minutes the components based on the composition shown in Tables 3 and 4below, and filtering the obtained solution through a membrane filterhaving opening of 1.0 μm. In Tables 3 and 4, the numerical value of eachcomponent is shown in wt % taking the mass of the ink composition as100%, and “the rest” that shows the amount of water means the amountmaking 100% in total with the components other than water.

TABLE 3 Y-1 Y-2 Y-3 Y-4 Y-5 M-1 M-2 M-3 M-4 M-5 C-1 C-2 C-3 C-4 C-5YELLOW-1 5 4 YELLOW-2 5 YELLOW-3 5 YELLOW-4 1 YELLOW-5 1.5 YELLOW-6 1.5YELLOW-7 0.5 MAGENTA-1 3.2 MAGENTA-2 3.2 MAGENTA-3 3.2 MAGENTA-4 3MAGENTA-5 4 CYAN-1 5 4.5 4 CYAN-2 0.5 1 CYAN-3 CYAN-4 5 CYAN-5 5Glycerol 12 12 12 12 12 10 10 10 10 10 12 12 12 12 12 Triethylene glycol10 10 10 10 10 2 2 2 2 2 11 11 11 11 11 Propylene glycol 3 5 2 2 2 2 2 2THGmBe 10 10 10 7 5 10 10 10 10 10 9 9 9 9 9 Sarfinol 465 (*1) 1 1 1 1 11 1 1 1 1 1 1 1 1 1 Urea 2 2 2 2 2 2.5 2.5 2.5 2.5 2.5 2 2 2 2 21,2-Hexanediol 2 3 3 2 5 5 2 2 2 2 2,5-Dimethyl-2,4-hexanediol 2 2 2Triethanolamine 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.1 0.1 0.1 0.10.1 2-Pyrrolidone 4 4 4 4 4 PROXEL XL2 (*2) 0.3 0.3 0.3 0.3 0.3 0.1 0.10.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Water The The The The The The The TheThe The The The The The The rest rest rest rest rest rest rest rest restrest rest rest rest rest rest Unit: wt % (*1) Manufactured by AirProducts and Chemical, Inc. (*2) Manufactured by Abesia

TABLE 4 LM-1 LM-2 ML-3 LM-4 LM-5 LC-1 LC-2 LC-3 LC-4 LC-5 MAGENTA-1 1MAGENTA-2 1 MAGENTA-3 1 MAGENTA-4 2 MAGENTA-5 2 CYAN-1 1.7 CYAN-2 1.7CYAN-3 1.7 CYAN-4 1.7 CYAN-5 1.5 Glycerol 12 12 12 12 12 11 11 11 11 11Triethylene glycol 10 10 10 10 8 4.5 4.5 2 4.5 3.5 Propylene glycol 22.5 1 TEGmBE 11 11 11 11 11 10 10 10 10 10 Sarfinol 465 (*1) 1 1 1 1 1 11 1 1 1 Urea 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 1,2-Hexanediol 33.4 3.4 3.4 3.4 2,5-Dimethyl-2,5-hexanediol 3 3.4 Triethanolamine 0.20.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 PROXEL XL2 (*2) 0.1 0.1 0.1 0.1 0.10.1 0.1 0.1 0.1 0.1 Water The The The The The The The The The The restrest rest rest rest rest rest rest rest rest Unit: wt % *1: Manufacturedby Air Products and Chemical, Inc. *2: Manufactured by Abesia(YELLOW-1):

(YELLOW-2):

(YELLOW-3):

Compound (YELLOW-1) can be synthesized according to the followingmethod.

(1) Synthesis of Compound (YELLOW-1b):

Sodium hydrogencarbonate (25.5 g) and 150 ml of ion exchange water wereheated at 40° C., and 25.0 g of cyanuric chloride (manufactured by TokyoChemical Industry Co., Ltd.) was added in parts by ⅕ with every 10minutes, and the mixture was stirred for 1 hour. The solution wasdropped to a mixed solution (8° C.) of 52.8 ml of hydrazine and 47 ml ofion exchange water so that the inner temperature was not higher than 10°C. The inner temperature was raised to 50° C. and the solution wasstirred for 30 minutes. The precipitated crystal was filtered to obtain23.4 g of Compound b (YELLOW-1b) (hydrazine derivative, m.p. >300° C.).The yield was 94.7%.

(2) Synthesis of Compound (YELLOW-1c):

The compound (YELLOW-1b) (hydrazine derivative) (35.0 g) was suspendedin 420 ml of ethylene glycol and stirred at inner temperature of 50° C.To the solution was added 95 ml of concentrated hydrochloric acid, andthen 60.1 g of pivaloyl acetonitrile (manufactured by Tokyo ChemicalIndustry Co., Ltd.), and the solution was stirred at 50° C. for 10hours. Concentrated hydrochloric acid (95 ml) and 145 ml of methanolwere added, and stirring was continued for further 8 hours. Thetemperature was lowered to room temperature, and the precipitatedcrystal was filtered to obtain 81.6 g of Compound c (5-aminopyrazolederivative, m.p. =233 to 235° C.). The yield was 94.2%. ¹H-NMR(DMSO-d6), δ value TMS standard: 1.2 to 1.3(18H, s)

(3) Synthesis of Compound (YELLOW-1e):

Compound d (manufactured by Tokyo Chemical Industry Co., Ltd.) (90.57 g)was suspended in 500 ml of H₂O, and 130 ml of concentrated hydrochloricacid was poured thereto and the inner temperature was lowered to 5° C.or lower. Subsequently, an aqueous solution containing 36.23 g of sodiumnitrite and 70 ml of the solution was dropped thereto at innertemperature of from 4 to 6° C., and the mixed solution was stirred atinner temperature of 5° C. or lower for 30 minutes. After that, 159 g ofsodium sulfite and 636 ml of H₂O were poured thereto while maintainingthe inner temperature at 20° C. or lower, and then 250 ml ofconcentrated hydrochloric acid was poured thereto at inner temperatureof 25° C., after stirring the solution for 1 hour at inner temperatureof 90° C., the inner temperature was lowered to room temperature, andthe reaction product was filtered and washed with 200 ml of water anddried to obtain 80.0 g of Compound e.

(4) Synthesis of Compound (YELLOW-1f):

After 28 ml of triethylamine was dropped into a suspension containing23.3 g of Compound e and 209 ml. of ethanol at room temperature, 12.2 gof ethoxymethylene malononitrile (a product of ALDRICH) was addedthereto in parts, and the suspension was refluxed for 3 hours. The innertemperature was lowered to room temperature, and the reaction solutionwas filtered, washed with 400 ml of isopropyl alcohol and dried, whereby23.57 g of Compound f was obtained.

(5) Synthesis of Compound (YELLOW-1):

Into 32.4 ml of sulfuric acid was poured 145.56 ml of acetic acid atinner temperature of 4° C. or lower, subsequently 15.9 ml of 40%nitrosylsulfuric acid (a product of ALDRICH) was dropped thereto atinner temperature of 7° C. while stirring.

Compound (YELLOW-1f) (32.4 g) was added in parts to the above solution,after stirring the solution at inner temperature at 10° C. for 60miniutes, 18.8 g of Compound C obtained by the addition of 1.83 g ofurea to the reaction solution was suspended in 470 ml of methanol, andto this solution was dropwise added diazonium salt at inner temperatureof higher than 0° C., and the solution was stirred at the sametemperature for 30 minutes, the temperature of the reaction solution wasincreased to room temperature, and then the solution was filtered,washed with methanol, and then with H₂O to thereby obtain crude crystal.Subsequently, the crude crystal was suspended in 400 ml of methanol, andthe suspension was stirred for 1 hour with refluxing, the temperaturewas lowered to room temperature, and the reaction solution was filtered,washed with methanol, with water, and then with methanol, dried at 75°C. overnight, whereby 34.4 g of free acid type crystal of Dye-11 wasobtained. The obtained crystal was made a 10 wt % aqueous solution withKOH (at 25° C., pH: about 8.3), IPA was added to the solution at innertemperature at 50° C. and crystallized, cooled, filtered, washed withIPA, and dried, whereby 35 g of (YELLOW-1) (potassium salt) wasobtained.

λmax=436.4 nm (H₂O), ε: 3.53×10⁴ (dm³·cm/mol)

-   (YELLOW-5): C.I. Direct Yellow 132-   (YELLOW-6): C.I. Direct Yellow 86-   (YELLOW-7): C.I. Direct Yellow 58

As magenta dyes, the following (MAGENTA-1), (MAGENTA-2), (MAGENTA-3),(MAGENTA4), and (MAGENTA-5) were used.

(MAGENTA-1) can be synthesized according to the following method.

(1) Synthesis of Compound (MAGENTA-1a):

5-Amino-3-tert-butyl-4-cyanopyrazole (1) (24.1 g) (0.147 mol), 45 ml ofconcentrated hydrochloric acid, 30 ml of acetic acid, and 45 ml ofpropionic acid were stirred at inner temperature of 0° C., and 10.1 g(0.147 mol) of sodium nitrite dissolved in 20 ml of water was dropped tothe above solution for 10 minutes. The solution was stirred for 30minutes as it was. Coupler component (2) (84.7 g) (0.147 mol) wasdissolved in 231 ml of methanesulfonic acid, 147 ml of acetic acid, and221 ml of propionic acid, the solution was stirred at 0° C., and theabove diazonium salt was added to the solution over 30 minutes. Afterthe addition of the diazonium salt, the reaction solution was furtherstirred for 30 minutes, and then the reaction solution was graduallyadded to 2,250 ml of water added with 750 g of ice and stirred.Precipitated compound (MAGENTA-1a) was filtered by suction and isolated.Yield: 73.8 g, 85%.

(2) Synthesis of Compound (MAGENTA-1b):

To 21 g (35.5 mmol) of the compound (MAGENTA-1a) were added 26.6 g (157mmol) of heterylizing agent (3), 21.7 g of potassium carbonate, and 147ml of DMSO, and the mixture was heated at inner temperature of 92° C.and stirred for 4 hours while nitrogen bubbling. After termination ofstirring, the temperature was lowered to room temperature, and thecompound (MAGENTA-1b) precipitated from the reaction system was filteredby suction and isolated. This crude crystal was further dispersed in 3liters of water to dissolve excessive amount of potassium carbonate,filtered by suction, whereby objective compound (MAGENTA-1b) wasobtained. Yield: 20.0 g, 63.5%. λmax=558 nm (DMF solution), m/Z(POSI)=858.

(3) Synthesis of Compound (MAGENTA-1):

Compound (MAGENTA-1b) (2 g) (2.33 mmol) was dispersed in 7 g of Sulforan(manufactured by Tokyo Chemical Industry Co., Ltd.), and 1.7 g of NISSOSULFAN (sulfur trioxide, manufactured by NISSO METALLOCHEMICAL CO.,LTD.) was dropped to the dispersion at inner temperature of 15° C. Aftertermination of dropping, the dispersion was allowed to react for 2 hoursat inner temperature of 70° C. After the reaction, the reaction solutionwas cooled to 20° C., and 2 ml of water was dropped to the reactionsolution. The inner temperature was lowered to 5° C., and 3.3 ml of a 25wt % sodium hydroxide aqueous solution was dropped thereto, and 0.8 mlof a 28 wt % methanol solution of sodium methoxide was further dropped.Further, 4 ml of methanol was dropped, and the precipitated inorganicsalt was filtered and washed with 2 ml of methanol. Potassium acetate (2g) and 5.6 ml of methanol were added to the filtrate, further 2.5 ml ofethanol was added to crystallize the dye, and the crystal was filteredby suction and washed with ethanol, whereby crude crystal of compound(MAGENTA-1) was obtained. The crude crystal containing the inorganicsalt was purified by demineralization with Sephadex LH-20 gelchromatography (eluent, water/methanol: 1/1 (v/v), manufactured byPharmacia) to obtain compound (MAGENTA-1).

Yield: 2 g, 66%.

λmax (DMSO)=567.1 nm, ε=46,900

Compound (MAGENTA-2) and Compound (MAGENTA-3) can also be synthesizedaccording to the similar synthesizing methods.

In Tables 3 and 4, as the cyan dyes, the following (CYAN-1), (CYAN-2),(CYAN-3), (CYAN-4) and (CYAN-5) were used.

One of rings A to D represents:

The remaining three represent:

 * is bonding position of the phthalocyanine ring.

Two of rings A to D represent:

The remaining two represent:

 * is bonding position of the phthalocyanine ring.

One of rings A to D represents:

The remaining three represent:

 * is bonding position of the phthalocyanine ring.

 * is bonding position of the phthalocyanine ring.

-   -   The mixture of the following Compounds I to III.    -   I. c=0, a+b=4    -   II. c=1, a+b=3    -   III. c=2, a+b=2        (CYAN-5): C.I. Direct Blue 199

Each of ink sets 1 to 10 was manufactured with each ink compositionprepared above according to the combination as shown in Table 5 below.

TABLE 5 Yellow Light Magenta Magenta Light Cyan Cyan Black Ink Set 1 Y-1LM-1 M-1 LC-1 C-1 B-7 Ink Set 2 Y-2 LM-2 M-2 LC-2 C-2 B-7 Ink Set 3 Y-3LM-3 M-3 LC-3 C-3 B-7 Ink Set 4 Y-4 LM-4 M-4 LC-4 C-4 B-7 Ink Set 5 Y-5LM-5 M-5 LC-5 C-5 B-7 Ink Set 6 ICY32 (EPSON) ICLM32 (EPSON) ICM32(EPSON) ICLC32 (EPSON) ICC32 (EPSON) B-7 Ink Set 7 BCI-7Y (Canon)BCI-7PM (Canon) BCI-7M (Canon) BCI-7PC (Canon) BCI-7C (Canon) B-7 InkSet 8 (Comparison) Y-1 LM-1 M-1 LC-1 C-1 B-8 Ink Set 9 (Comparison) Y-2LM-2 M-2 LC-2 C-2 B-8 Ink Set 10 (Comparison) Y-3 LM-3 M-3 LC-3 C-3 B-8

Each of these inks was filled in a corresponding ink cartridge of InkJet Printer PMG820 (manufactured by SEIKO EPSON CORPORATION). In ink set6, genuine inks for PMG820 were used as they were except for the blackink, and in ink set 7, ink of each color of BCI-7 (manufactured by CanonInc.) was extracted and filled in a corresponding ink cartridge forPMG800, and these ink cartridges were loaded on PMG800, and printing wasperformed.

Evaluation:

-   1) Regarding image preservation stability, a black solid image of    R:0, G:0, B:0 was made with imaging software Photoshop (manufactured    by Adobe Systems Incorporated), and a black solid image was printed.    The evaluations of the following 2) and 3) were performed with the    obtained image. In evaluation of image preservation stability, the    density of step pattern was measured with densitometer X-rite 310    loading Status A Filter, and the change in density was measured.-   2) Regarding light fastness, after measuring densities (D_(B),    D_(G), D_(R)) Ci just after printing with X-rite 310, the image was    irradiated with a xenon lamp (85,000 lux) for 10 days with a weather    meter (manufactured by Atlas). After that, the densities Cf were    measured, and light fastness was evaluated by finding the residual    rate of dye [(Cf/Ci)×100].

The case where the residual rate of dye is 80% or more in all of D_(B),D_(G), D_(R) is graded A, the case of from 70 to 80% even at a part isgraded B, and the case of less than 70% even at a part is graded C.

-   3) Regarding ozone-proofness, after measuring densities (D_(B),    D_(G), D_(R)) Ci just after printing with X-rite 310, the image was    exposed to ozone gas in a box set at ozone gas concentration of 5    ppm for 170 hours. After that, densities Cf were measured, and    ozone-proofness was evaluated by finding the residual rate of dye    [(Cf/Ci)×100].

The ozone gas concentration in the box was set with an ozone gas monitor(model OZG-EM-01, manufactured by APPLICS).

The case where the residual rate of dye is 80% or more in all of D_(B),D_(G), D_(R) is graded A, the case of from 70 to 80% even at a part isgraded B, and the case of less than 70% even at a part is graded C.

-   4) Regarding image blotting of black ink under high humidity    condition, the same black-and-white checkered image used in Example    1, a black-and-magenta checkered image formed by making the white    area of the above image OD=1.0 of magenta, and a black-and-cyan    checkered image formed by making the white area OD=1.0 of cyan, were    prepared, and respective image samples were formed. With each image    sample, blotting of each image after being allowed to stand on the    conditions of 25° C. 90% RH for 7 days was visually judged.

An image having no blotting in the area between the lines of checker isgraded A, an image where the hue of color correction dye is observed alittle is graded B, and an image where the color correction dye isclearly blotted on the white area is graded C.

-   5) Regarding bronzing evaluation, the glossiness of the obtained    print was measured (measuring angle: 60°)with a gloss meter (PG-1M,    manufactured by Nippon Denshoku Industries Co., Ltd.). Printing was    performed on two environmental conditions of 20° C. 40% RH and    35° C. 60% RH. The obtained glossiness and the rising value computed    according to the following expression were taken as the reference of    judging the degree of generation of bronzing phenomenon, and    evaluated on the basis of the following criteria.    Rising value=glossiness (printed matter)−glossiness (recording    medium)    Criteria of Evaluation:-   Grade A: Less than 15-   Grade B: 15 or higher and less than 35-   Grade C: 35 or higher and less than 55-   Grade D: 55 or higher

The results of evaluation are shown in Table 6 below.

TABLE 6 Light Ozone Blotting Black Ink Density Fastness ProofnessBronzing of Image Ink set 1 A A A A A Ink set 2 A A A A A Ink set 3 A AA A A Ink set 4 A A A A A Ink set 5 A A A A A Ink set 6 A A A A A Inkset 7 A A A A A Ink set 8 B A A A A (Comparison) Ink set 9 B A A A A(Comparison) Ink set 10 B A A A A (Comparison)

In the ink set using the black ink composition of the invention, in ablack solid part of color print capable of ejecting yellow, magenta andcyan other than black ink, printed matters of high density black can beobtained without deteriorating light fastness, ozone-proofness,bronzing, and blotting of images.

When the same tests were carried out except for changing image-receivingsheets, almost the same results as in Table 6 were obtained As theimage-receiving sheets, Kassai (Photo Finish Advance, manufactured byFuji Photo Film Co., Ltd.) double weight Hi, Kassai (Photo Finish Pro,manufactured by Fuji Photo Film Co., Ltd.), photographic paper CRISPIA(high glossy, manufactured by SEIKO EPSON CORPORATION), photographicpaper (glossy, manufactured by SEIKO EPSON CORPORATION), ProfessionalPhoto Paper (manufactured by Canon Inc.), Super Photo Paper(manufactured by Canon Inc.), and Photolike QP (photographic imagequality, manufactured by KONICA MINOLTA HOLDINGS, INC.) super doubleweight, were used.

The ink according to the invention is fast to light and ozone gas,therefore, an image excellent in preservation stability by aging andhaving high density can be obtained.

The ink according to the invention can provide an image excellent inweatherproof and stability of hue and having high density.

Further, the ink according to the invention can provide an imagerestrained from bronze glossiness, free from blotting, and excellent indiscoloration balance, and having high density.

The entire disclosure of each and every foreign patent application fromwhich the benefit of foreign priority has been claimed in the presentapplication is incorporated herein by reference, as if fully set forth.

1. An ink composition, which comprises: at least two kinds ofwater-soluble dyes each having the maximum wavelength of an absorptionspectrum in an aqueous solvent of from 550 to 700 nm, wherein the atleast two kinds of water-soluble dyes include: at least one selectedfrom the group consisting of a compound represented by formula (L-1) anda salt of the compound represented by formula (L-1); and at least onecompound having a naphthalene ring substituted with at least onehydroxyl group and three or more azo groups:

wherein A and B each independently represents an aromatic group that maybe substituted or a heterocyclic group that may be substituted, and A isa monovalent group and B is a divalent group; T₁ and T₂ eachindependently represents ═CR₄₃—or —CR₄₄═, or either one represents anitrogen atom and the other represents ═CR₄₃—or —CR₄₄═; V₁, R₄₃ and R₄₄each independently represents a hydrogen atom, a halogen atom, an alkylgroup, an alkenyl group, an alkynyl group, an aralkyl group, an arylgroup, a heterocyclic group, a cyano group, a carboxyl group, acarbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, aheterocyclic oxycarbonyl group, an acyl group, a hydroxyl group, analkoxyl group, an aryloxy group, a heterocyclic oxy group, a silyloxygroup, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxygroup, an aryloxycarbonyloxy group, an amino group, an acylamino group,a ureido group, a sulfamoylamino group, an alkoxycarbonylamino group, anaryloxycarbonylamino group, an alkylsulfonylamino group, anarylsulfonylamino group, a heterocyclic sulfonylamino group, a nitrogroup, an alkylthio group, an arylthio group, a heterocyclic thio group,an alkylsulfonyl group, an arylsulfonyl group, a heterocyclic sulfonylgroup, an alkylsulfinyl group, an arylsulfinyl group, a heterocyclicsulfinyl group, a sulfamoyl group or a sulfo group, and each of thesegroups may further be substituted; R₄₁and R₄₂, each independentlyrepresents a hydrogen atom, an alkyl group, an alkenyl group, an alkynylgroup, an aralkyl group, an aryl group, a heterocyclic group, an acylgroup, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoylgroup, an alkylsulfonyl group, an arylsulfonyl group or a sulfamoylgroup, and each of these groups may further have a substituted, providedthat R₄₁ and R₄₂ do not represent a hydrogen atom at the same time, andR₄₃ and R₄₁, or R₄₁ and R₄₂ may be bonded to each other to form a 5- or6-membered ring, provided that the compound represented by formula (L-1)contains at least one ionic hydrophilic group.
 2. The ink compositionaccording to claim 1, wherein the compound represented by formula (L-1)is a compound represented by formula (L-2):

wherein X represents an N atom or ═CW₁—; W₁ represents an electronattracting group having a Hammett's substitution constant σp value of0.20 or more; A, V₁, T₁, T₂, R₄₁ and R₄₂ respectively have the samemeaning as A, V₁, T₁, T₂, R₄₁ and R₄₂ in formula (L-1); and W has thesame meaning as V₁ in formula (L-1).
 3. The ink composition according toclaim 2, wherein the compound represented by formula (L-2) is a compoundrepresented by formula (L-3):

wherein V₁, W, X, T₁, T₂, R₄₁ and R₄₂ respectively have the same meaningas V₁, W, X, T₁, T₂, R₄₁ and R₄₂ in formula (L-2); and X₁, X₂, X₃, X₄,X₅, X₆ and X₇ each represents a monovalent group.
 4. The ink compositionaccording to claim 1, which comprises at least one compound representedby formula (L-1) and at least one compound represented by formula (L-4)different in structure from each other:

wherein R₄₃ has the same meaning as R₄₃ in formula (L-1); R₄₄ has thesame meaning as R₄₄ in formula (L-1); R₄₅ and R₄₆ each has the samemeaning as R₄₁ and R₄₂ in formula (L-1); R₄₁ and R₄₂ each has the samemeaning as R₄₁ and R₄₂ in formula (L-1); W has the same meaning as V₁ informula (L-1); and X₁, X₂, X₃, X₄, X₅, X₆ and X₇ each represents amonovalent group.
 5. The ink composition according to claim 1, whichcomprises at least one compound represented by formula (L-1) and atleast one compound represented by formula (L-5) different in structurefrom each other:

wherein R₄₃ has the same meaning as R₄₃ in formula (L-1); R₄₄ has thesame meaning as R₄₄ in formula (L-1); R₄₅ and R₄₆ each has the samemeaning as R₄₁ and R₄₂ in formula (L-1); R₄₁ and R₄₂ each has the samemeaning as R₄₁ and R₄₂ in formula (L-1); W has the same meaning as V₁ informula (L-1); W₁₁ represents an electron attracting group having aHammett's substitution constant σp value of 0.20 or more; and X₁, X₂,X₃, X₄, X₅, X₆ and X₇ each represents a monovalent group.
 6. The inkcomposition according to claim 1, wherein the number of azo groups ofthe compound having a naphthalene ring substituted with at least onehydroxyl group and three or more azo groups is five or less.
 7. The inkcomposition according to claim 1, wherein the compound having anaphthalene ring substituted with at least one hydroxyl group and threeor more azo groups contains one or more sulfonic acid group(s), one ormore carboxyl group(s), or one or more sulfonic acid group(s) and one ormore carboxyl group(s).
 8. The ink composition according to claim 1,wherein the compound having a naphthalene ring substituted with at leastone hydroxyl group and three or more azo groups is a compound selectedfrom the group consisting of a compound represented by any of formulae(L-6), (L-6a), (L-7) and (L-8) and a salt of the compound represented byany of formulae (L-6), (L-6a), (L-7) and (L-8):

wherein R₁₁ and R₁₂ each independently represents a hydrogen atom; ahalogen atom; a cyano group; a carboxyl group; a sulfo group; asulfamoyl group that may be substituted with an alkyl group or a phenylgroup; a phosphoric acid group; a nitro group; an acyl group; a ureidogroup; an alkyl group having from 1 to 4 carbon atoms that may besubstituted with a hydroxyl group or an alkoxyl group having from 1 to 4carbon atoms; an alkoxyl group having from 1 to 4 carbon atoms or anacylamino group that may be substituted with a hydroxyl group, analkoxyl group having from 1 to 4 carbon atoms, a sulfo group or acarboxyl group; E represents a phenyl group or a naphthyl group, whichmay be substituted with a halogen atom; a cyano group; a carboxyl group;a sulfo group; a sulfamoyl group that may be substituted with an alkylgroup or a phenyl group; a phosphoric acid group; a nitro group; an acylgroup; a ureido group; an alkyl group having from 1 to 4 carbon atomsthat may be substituted with a hydroxyl group or an alkoxyl group havingfrom 1 to 4 carbon atoms; an alkoxyl group having from 1 to 4 carbonatoms or an acylamino group that may be substituted with a hydroxylgroup, an alkoxyl group having from 1 to 4 carbon atoms, a sulfo groupor a carboxyl group; and n₁ represents 0 or 1;

wherein A represents formula (L-6a-1), and the substitution position ofA is the m- or p-position to the azo group; R¹ and R² each independentlyrepresents a hydrogen atom; a halogen atom; a cyano group; a carboxylgroup; a sulfo group; a sulfamoyl group; an N-alkylaminosulfonyl group;an N-phenylamino- sulfonyl group; a phospho group; a nitro group; anacyl group; a ureido group; an alkyl group having from 1 to 4 carbonatoms that may be substituted with a hydroxyl group or an alkoxyl grouphaving from 1 to 4 carbon atoms; an alkoxyl group having from 1 to 4carbon atoms that may be substituted with a hydroxyl group, an alkoxylgroup having from 1 to 4 carbon atoms, a sulfo group or a carboxylgroup; or an acylamino group that may be substituted with an alkoxylgroup having from 1 to 4 carbon atoms, a sulfo group or a carboxylgroup; R³ and R⁴ each independently represents a hydrogen atom; ahalogen atom; a cyano group; a carboxyl group; a sulfo group; a nitrogroup; an alkyl group having from 1 to 4 carbon atoms; a hydroxyl group;or an alkoxyl group having from 1 to 4 carbon atoms that may besubstituted with an alkoxyl group having from 1 to 4 carbon atoms or asulfo group; and n represents 0 or 1;

wherein R⁵ represents a cyano group; a carboxyl group; an alkyl grouphaving from 1 to 4 carbon atoms; an alkoxycarbonyl group having from 1to 4 carbon atoms; or a phenyl group; R⁶, R⁷ and R⁸ each independentlyrepresents a hydrogen atom; a halogen atom; a cyano group; a carboxylgroup; a sulfo group; a nitro group; an alkyl group having from 1 to 4carbon atoms; an alkoxyl group having from 1 to 4 carbon atoms that maybe substituted with a hydroxyl group, an alkoxyl group having from 1 to4 carbon atoms or a sulfo group; or an acylamino group that may besubstituted with a hydroxyl group, an alkoxyl group having from 1 to 4carbon atoms or a sulfo group;

wherein G and J each independently represents a phenyl group or anaphthyl group that may be substituted, or a 5- or 6-membered aromaticheterocyclic group bonding to the azo group via a carbon atom, and eachof G and J contains at least one or more carboxyl group(s) or sulfogroup(s); one of X and Y represents a hydroxyl group, and the otherrepresents an amino group; and l₂, m₂ and n₂ each independentlyrepresents 1 or 2;

wherein R₂₁ represents a phenyl group having a substituent, or anaphthyl group having a substituent; R₂₂ represents a phenylene grouphaving a substituent, or a naphthylene group having a substituent; R₂₃represents a 5- to 7-membered heterocyclic group having at least onedouble bond and a substituent; and the substituents in R₂₁, R₂₂ and R₂₃are each independently selected from the group consisting of OH, SO₃H,PO₃H₂, CO₂H, NO₂, NH₂, an alkyl group having from 1 to 4 carbon atoms,an alkyl group having from 1 to 4 carbon atoms and a substituent, analkoxyl group having from 1 to 4 carbon atoms, an alkoxyl group havingfrom 1 to 4 carbon atoms and a substituent, an amino group, an aminogroup having a substituent and a phenyl group having a substituent. 9.An ink composition, which comprises: at least two kinds of water-solubledyes each having the maximum wavelength of an absorption spectrum in anaqueous solvent of from 550 to 700 nm, wherein the at least two kinds ofwater-soluble dyes include: at least one compound selected from thegroup consisting of a compound represented by formula (L-1)

wherein A and B each independently represents an aromatic group that maybe substituted or a heterocyclic group that may be substituted, and A isa monovalent group and B is a divalent group; T₁ and T₂ eachindependently represents ═CR₄₃—or —CR₄₄═, or either one represents anitrogen atom and the other represents ═CR₄₃—or —CR₄₄ ═; V₁, R₄₃ and R₄₄each independently represents a hydrogen atom, a halogen atom, an alkylgroup, an alkenyl group, an alkynyl group, an aralkyl group, an arylgroup, a heterocyclic group, a cyano group, a carboxyl group, acarbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, aheterocyclic oxycarbonyl group, an acyl group, a hydroxyl group, analkoxyl group, an aryloxy group, a heterocyclic oxy group, a silyloxygroup, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxygroup, an aryloxycarbonyloxy group, an amino group, an acylamino group,a ureido group, a sulfamoylamino group, an alkoxycarbonylamino group, anaryloxycarbonylamino group, an alkylsulfonylamino group, anarylsulfonylamino group, a heterocyclic sulfonylamino group, a nitrogroup, an alkylthio group, an arylthio group, a heterocyclic thio group,an alkylsulfonyl group, an arylsulfonyl group, a heterocyclic sulfonylgroup, an alkylsulfinyl group, an arylsulfinyl group a heterocyclicsulfinyl group, a sulfamoyl group or a sulfo group, and each of thesegroups may further be substituted; R₄₁, R₄₂ each independentlyrepresents a hydrogen atom, an alkyl group, an alkenyl group, an alkynylgroup, an aralkyl group, an aryl group, a heterocyclic group, an acylgroup, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoylgroup, an alkylsulfonyl group, an arylsulfonyl group or a sulfamoylgroup, and each of these groups may further have a substituted, providedthat R₄₁ and R₄₂ do not represent a hydrogen atom at the same time, andR₄₃ and R₄₁ or R₄₁ and R₄₂ may be bonded to each other to form a 5- or6-membered ring, provided that the compound represented by formula (L-1)contains at least one ionic hydrophilic group, a compound represented byformula (L-2),

wherein X represents an N atom or ═CW₁—; W₁ represents an electronattracting group having a Hammett's substitution constant σp value of0.20 or more; A, V₁, T₁, T₂, R₄₁ and R₄₂ respectively have the samemeaning as A, V₁, T₁, T₂, R₄₁ and R₄₂ in formula (L-1); and W has thesame meaning as V₁ in formula (L-1), a compound represented by formula(L-3),

wherein V₁, W, X, T₁, T₂, R₄₁ and R₄₂ respectively have the same meaningas V₁, W, X, T₁, T₂,R₄₁ and R₄₂ in formula (L-2); and X₁, X₂, X₃, X₄,X₅, X₆ and X₇ each represents a monovalent group, a compound representedby formula (L-4)

wherein R₄₃ has the same meaning as R₄₃ in formula (L-1); R₄₄ has thesame meaning as R₄₄ in formula (L-1); R₄₅ and R₄₆ each has the samemeaning as R₄₁ and R₄₂ in formula (L-1); R₄₁ and R₄₂ each has the samemeaning as R₄₁ and R₄₂ in formula (L-1); W has the same meaning as V₁ informula (L-1); and X₁, X₂, X₃, X₄, X₅, X₆ and X₇ each represents amonovalent group, and a compound represented by formula (L-5);

wherein R₄₃ has the same meaning as R₄₃ in formula (L-1); R₄₄ has thesame meaning as R₄₄ in formula (L-1); R₄₅ and R₄₆ each has the samemeaning as R₄₁ and R₄₂ in formula (L-1); R₄₁ and R₄₂ each has the samemeaning as R₄₁ and R₄₂ in formula (L-1); W has the same meaning as V₁ informula (L-1); W₁₁ represents an electron attracting group having aHammett's substitution constant σp value of 0.20 or more; and X₁, X²,X₃, X₄, X₅, X₆ and X₇ each represents a monovalent group, and at leastone compound selected from the group consisting of a compoundrepresented by any of formulae (L-6),

wherein R₁₁ and R₁₂ each independently represents a hydrogen atom; ahalogen atom; a cyano group; a carboxyl group; a sulfo group; asulfamoyl group that may be substituted with an alkyl group or a phenylgroup; a phosphoric acid group; a nitro group; an acyl group; a ureidogroup; an alkyl group having from 1 to 4 carbon atoms that may besubstituted with a hydroxyl group or an alkoxylyl group having from 1 to4 carbon atoms; an alkoxyl group having from 1 to 4 carbon atoms or anacylamino group that may be substituted with a hydroxyl group, analkoxyl group having from 1 to 4 carbon atoms, a sulfo group or acarboxyl group; E represents a phenyl group or a naphthyl group, whichmay be substituted with a halogen atom; a cyano group; a carboxyl group;a sulfo group; a sulfamoyl group that may be substituted with an alkylgroup or a phenyl group; a phosphoric acid group; a nitro group; an acylgroup; a ureido group; an alkyl group having from 1 to 4 carbon atomsthat may be substituted with a hydroxyl group or an alkoxyl group havingfrom 1 to 4 carbon atoms; an alkoxyl group having from 1 to 4 carbonatoms or an acylamino group that may be substituted with a hydroxylgroup, an alkoxyl group having from 1 to 4 carbon atoms, a sulfo groupor a carboxyl group; and n₁ represents 0 or 1; (L-6a),

wherein A represents formula (L-6a-1), and the substitution position ofA is the m- or p-position to the azo group; R¹ and R² each independentlyrepresents a hydrogen atom; a halogen atom; a cyano group; a carboxylgroup; a sulfo group; a sulfamoyl group; an N-alkylaminosulfonyl group;an N-phenylamino-sulfonyl group; a phospho group; a nitro group; an acylgroup; a ureido group; an alkyl group having from 1 to 4 carbon atomsthat may be substituted with a hydroxyl group or an alkoxyl group havingfrom 1 to 4 carbon atoms; an alkoxyl group having from 1 to 4 carbonatoms that may be substituted with a hydroxyl group, an alkoxyl grouphaving from 1 to 4 carbon atoms, a sulfo group or a carboxyl group; oran acylamino group that may be substituted with an alkoxyl group havingfrom 1 to 4 carbon atoms, a sulfo group or a carboxyl group; R³ and R⁴each independently represents a hydrogen atom; a halogen atom; a cyanogroup; a carboxyl group; a sulfo group; a nitro group; an alkyl grouphaving from 1 to 4 carbon atoms; a hydroxyl group; or an alkoxyl grouphaving from 1 to 4 carbon atoms that may be substituted with an alkoxylgroup having from 1 to 4 carbon atoms or a sulfo group; and n represents0 or 1;

wherein R⁵ represents a cyano group; a carboxyl group; an alkyl grouphaving from 1 to 4 carbon atoms; an alkoxycarbonyl group having from 1to 4 carbon atoms; or a phenyl group; R⁶, R⁷ and R⁸ each independentlyrepresents a hydrogen atom; a halogen atom; a cyano group; a carboxylgroup; a sulfo group; a nitro group; an alkyl group having from 1 to 4carbon atoms; an alkoxyl group having from 1 to 4 carbon atoms that maybe substituted with a hydroxyl group, an alkoxyl group having from 1 to4 carbon atoms or a sulfo group; or an acylamino group that may besubstituted with a hydroxyl group, an alkoxyl group having from 1 to 4carbon atoms or a sulfo group; (L-7)

wherein G and J each independently represents a phenyl group or anaphthyl group that may be substituted, or a 5- or 6-membered aromaticheterocyclic group bonding to the azo group via a carbon atom, and eachof G and J contains at least one or more carboxyl group(s) or sulfogroup(s); one of X and Y represents a hydroxyl group, and the otherrepresents an amino group; and l₂, m₂, and n₂, each independentlyrepresents 1 or 2, and (L-8)

wherein R₂₁ represents a phenyl group having a substituent, or anaphthyl group having a substituent; R ₂₂ represents a phenylene grouphaving a substituent, or a naphthylene group having a substituent; R₂₃represents a 5- to 7-membered heterocyclic group having at least onedouble bond and a substituent; and the substituents in R₂₁, R₂₂ and R₂₃are each independently selected from the group consisting of OH, SO₃H,PO₃H₂, CO₂H, NO₂, NH₂, an alkyl group having from 1 to 4 carbon atoms,an alkyl group having from 1 to 4 carbon atoms and a substituent, analkoxyl group having from 1 to 4 carbon atoms, an alkoxyl group havingfrom 1 to 4 carbon atoms and a substituent, an amino group, an aminogroup having a substituent and a phenyl group having a substituent and asalt of the compound represented by any of formulae (L-6), (L-6a), (L-7)and (L-8).
 10. The ink composition according to claim 8, wherein thecompound represented by formula (L-8) is a compound represented byformula (L-9):

wherein R₃₁ to R₃₉ each independently represents a group selected fromthe group consisting of H, OH, SO₃H, PO₃H₂, CO₂H, NO₂ and NH₂.
 11. Theink composition according to claim 1, which further comprises at leastone kind of water-soluble dye having the maximum wavelength of anabsorption spectrum in an aqueous solvent of from 400 to 520 nm.
 12. Theink composition according to claim 11, which comprises the at least onekind of water-soluble dye having the maximum wavelength of an absorptionspectrum in an aqueous solvent of from 400 to 520 nm in an amount offrom 0.1 to 4 mass%.
 13. An ink set, which comprises at least one kindof an ink composition according to claim
 1. 14. A recording method,which comprises: applying an ink composition according to claim 1 to arecording medium to conduct recording.
 15. A recording method, whichcomprises: loading an ink set according to claim 13 on a recordingapparatus; and applying an ink from the recording apparatus to arecording medium to conduct recording.
 16. The recording methodaccording to claim 14, which comprises: ejecting the ink compositionfrom an ink jet nozzle to a recording medium to conduct recording.